{
 "company": "duolingo",
 "as_of": "2026-10-01",
 "choices": [
  {
   "id": "duolingo-p01",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Private beta",
   "statement": "Duolingo opened a private beta on November 27, 2011 and released publicly on June 19, 2012.",
   "event_date": "2011-11-27",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL16"
   ]
  },
  {
   "id": "duolingo-p02",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Learning by translating",
   "statement": "The first product had learners translate real web content as they practised, with the translations sold to publishers.",
   "event_date": "2012",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL2"
   ]
  },
  {
   "id": "duolingo-p06",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Streak at launch",
   "statement": "Duolingo launched with a streak, first tied to a daily experience-points goal.",
   "event_date": "2012",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL28"
   ]
  },
  {
   "id": "duolingo-g02",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Translation buyers",
   "statement": "Learner translations were sold to CNN and BuzzFeed; the business found only two customers and rivals undercut prices.",
   "event_date": "2012",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL2"
   ]
  },
  {
   "id": "duolingo-g01",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Free with no ads",
   "statement": "Duolingo launched promising no ads, subscriptions or in-app purchases; early employees threatened to quit if it charged users.",
   "event_date": "2012-06",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL3"
   ]
  },
  {
   "id": "duolingo-p03",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Full iPhone app",
   "statement": "Two interns built a full iOS app rather than a companion app; it became the top education app within a week and Apple's iPhone App of the Year for 2013.",
   "event_date": "2012-11",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL2"
   ]
  },
  {
   "id": "duolingo-p05",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Translation retired",
   "statement": "By the end of 2013 Duolingo shut down the translation service; an engineer said teaching through translation conflicted with teaching the language well.",
   "event_date": "2013",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL2"
   ]
  },
  {
   "id": "duolingo-g03",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "No marketing budget",
   "statement": "Gotthilf was hired to grow Duolingo with no budget and never turned on paid ads.",
   "event_date": "2013",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL27"
   ]
  },
  {
   "id": "duolingo-g06",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Brazil and Latin America",
   "statement": "Gotthilf began as a consultant growing Duolingo in Brazil, then Chile and Argentina.",
   "event_date": "2013",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL27"
   ]
  },
  {
   "id": "duolingo-p04",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Android app",
   "statement": "An Android app followed in May 2013.",
   "event_date": "2013-05",
   "date_precision": "month",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL16"
   ]
  },
  {
   "id": "duolingo-g11",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Ad test",
   "statement": "Before Plus, Duolingo tested a small ad at the end of a lesson to see whether it reduced use.",
   "event_date": "2016",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL21"
   ]
  },
  {
   "id": "duolingo-g09",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Duolingo Plus",
   "statement": "Duolingo Plus launched on Android at $9.99 a month for ad-free and offline lessons, with learning content kept free.",
   "event_date": "2017-04-21",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL21"
   ]
  },
  {
   "id": "duolingo-p21",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Leagues test",
   "statement": "Weekly leaderboards were first tested in 2018 with five leagues, later expanded to ten.",
   "event_date": "2018",
   "date_precision": "year",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL41"
   ]
  },
  {
   "id": "duolingo-p09",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Badges",
   "statement": "Badges failed as a minimal test and, after a two to three month redesign, became what Gotthilf called probably the most successful experiment.",
   "event_date": "2018-04",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL5"
   ]
  },
  {
   "id": "duolingo-g05",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "PR launches abroad",
   "statement": "Growth launched Duolingo through press in Japan, China, India, Korea and Turkey, insisting that coverage linked to the app.",
   "event_date": "2018-04",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL5"
   ]
  },
  {
   "id": "duolingo-g07",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Use before sign-up",
   "statement": "Letting people try lessons before signing up raised conversion.",
   "event_date": "2018-04",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL5"
   ]
  },
  {
   "id": "duolingo-p22",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "One-lesson streak",
   "statement": "About November 2019 Duolingo separated the streak from the daily XP goal so one lesson extended it; the test raised day-14 retention 3.3% and daily active learners 1%.",
   "event_date": "2019",
   "date_precision": "year",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL40"
   ]
  },
  {
   "id": "duolingo-p19",
   "business": "Duolingo English Test",
   "category": "product",
   "dimension": "Online English test",
   "statement": "The Duolingo English Test is taken online at home in 25 to 35 minutes, against two to three hours at a test centre for TOEFL or IELTS.",
   "event_date": "2020-05",
   "date_precision": "month",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL13"
   ]
  },
  {
   "id": "duolingo-g14",
   "business": "Duolingo English Test",
   "category": "go_to_market",
   "dimension": "DET price",
   "statement": "The English test cost $49 against more than $200 for TOEFL or IELTS.",
   "event_date": "2020-05",
   "date_precision": "month",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL13"
   ]
  },
  {
   "id": "duolingo-g15",
   "business": "Duolingo English Test",
   "category": "go_to_market",
   "dimension": "DET acceptance",
   "statement": "About 1,000 programs began accepting the test during the pandemic, taking the total to about 2,000; by 2025 it was over 6,100.",
   "event_date": "2020-05-19",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL13"
   ]
  },
  {
   "id": "duolingo-g27",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "European ad spend",
   "statement": "Sensor Tower estimated Duolingo's digital ad spend in Europe at about $100 thousand in 2021, against over $20 million for Babbel in Germany and the UK.",
   "event_date": "2021",
   "date_precision": "year",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL46"
   ]
  },
  {
   "id": "duolingo-g10",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Convenience features",
   "statement": "Plus sold convenience: no ads, offline lessons, streak repair, unlimited hearts and test-outs; von Ahn rejected paying to learn faster.",
   "event_date": "2021-05",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL3"
   ]
  },
  {
   "id": "duolingo-g13",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Geographic pricing",
   "statement": "Von Ahn preferred to charge heavy users in rich countries and not users on low-end phones in India.",
   "event_date": "2021-05",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL3"
   ]
  },
  {
   "id": "duolingo-p12",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "BirdBrain student model",
   "statement": "A model called BirdBrain predicts the probability that any learner answers any exercise correctly, trained on over half a billion daily exercises.",
   "event_date": "2021-06",
   "date_precision": "month",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL4"
   ]
  },
  {
   "id": "duolingo-g20",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "IPO",
   "statement": "Duolingo listed on Nasdaq at $102 a share.",
   "event_date": "2021-07-28",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL17"
   ]
  },
  {
   "id": "duolingo-g26",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Top-grossing while free",
   "statement": "At the IPO von Ahn wrote that the app had become the top-grossing education app on Google Play and the App Store while all learning content stayed free.",
   "event_date": "2021-07-30",
   "date_precision": "day",
   "evidence_kind": "participant_account",
   "sources": [
    "DL42"
   ]
  },
  {
   "id": "duolingo-g16",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "TikTok owl",
   "statement": "A social media coordinator took over the dormant TikTok account in Q3 2021 and built it to 8.2 million followers with an unruly owl mascot.",
   "event_date": "2021-09",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL14"
   ]
  },
  {
   "id": "duolingo-p20",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Efficacy study",
   "statement": "A company-funded study found learners completing beginning Spanish or French courses (median 112 hours) reached reading and listening levels of fourth-semester university students.",
   "event_date": "2022",
   "date_precision": "year",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL19"
   ]
  },
  {
   "id": "duolingo-p11",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Streak Freeze",
   "statement": "Letting learners hold two Streak Freezes raised daily active learners 0.38%; new streak animations raised new users' seven-day retention 1.7%.",
   "event_date": "2022-01",
   "date_precision": "month",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL24"
   ]
  },
  {
   "id": "duolingo-p14",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Path redesign",
   "statement": "The course interface was redesigned in August 2022.",
   "event_date": "2022-08",
   "date_precision": "month",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL16"
   ]
  },
  {
   "id": "duolingo-p15",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "New subjects",
   "statement": "Duolingo added math (announced August 2022), music (October 2023) and chess (April 2025).",
   "event_date": "2022-08-27",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL16"
   ]
  },
  {
   "id": "duolingo-p10",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Leaderboards",
   "statement": "Weekly competitive leagues, copied from FarmVille 2, raised learning time 17% and tripled highly engaged learners.",
   "event_date": "2023",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL1"
   ]
  },
  {
   "id": "duolingo-g21",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Referral program",
   "statement": "A referral program offering free Super Duolingo raised new users by only 3%.",
   "event_date": "2023",
   "date_precision": "year",
   "evidence_kind": "participant_account",
   "sources": [
    "DL1"
   ]
  },
  {
   "id": "duolingo-p16",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Duolingo Max",
   "statement": "Duolingo Max added GPT-4 Roleplay conversations and Explain My Answer, first for Spanish and French on iOS.",
   "event_date": "2023-03-14",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL12"
   ]
  },
  {
   "id": "duolingo-g19",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Max price",
   "statement": "Max cost $29.99 a month or $167.99 a year.",
   "event_date": "2023-03-14",
   "date_precision": "day",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL12"
   ]
  },
  {
   "id": "duolingo-g08",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Effectiveness messaging",
   "statement": "A weekly social post and PR pitches carried evidence that Duolingo worked, alongside a weekly mission post.",
   "event_date": "2023-10",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL27"
   ]
  },
  {
   "id": "duolingo-g12",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Mission on the paywall",
   "statement": "Adding that paying makes language learning accessible to millions improved paid conversion.",
   "event_date": "2023-10",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL27"
   ]
  },
  {
   "id": "duolingo-g18",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Word of mouth share",
   "statement": "About 90% of user growth came from word of mouth, according to the VP of Engineering.",
   "event_date": "2024-04",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL15"
   ]
  },
  {
   "id": "duolingo-p08",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Three-minute lessons",
   "statement": "Lessons were cut to a few minutes so they could be done while waiting for a bus.",
   "event_date": "2024-11",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL6"
   ]
  },
  {
   "id": "duolingo-p13",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Notification timing",
   "statement": "A model trained over years chooses when to send each learner a reminder.",
   "event_date": "2024-11",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL6"
   ]
  },
  {
   "id": "duolingo-g04",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "No paid acquisition",
   "statement": "Von Ahn said paying about $30 per user made no sense while the company earned nothing, which forced the focus onto retention.",
   "event_date": "2024-11",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL6"
   ]
  },
  {
   "id": "duolingo-g17",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Owl-driven users",
   "statement": "Von Ahn said about 15% of users came from the owl's social media presence.",
   "event_date": "2024-11",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL6"
   ]
  },
  {
   "id": "duolingo-p07",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "One-lesson streak",
   "statement": "The streak was changed from an XP goal to one lesson a day; a later test that made extending even easier attracted the least engaged users and was not kept.",
   "event_date": "2024-12",
   "date_precision": "month",
   "evidence_kind": "participant_account",
   "sources": [
    "DL28"
   ]
  },
  {
   "id": "duolingo-g25",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Family plan and app stores",
   "statement": "Super offered a family plan for up to six; 62% of 2025 revenue came through Apple's App Store and 20% through Google Play.",
   "event_date": "2025",
   "date_precision": "year",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL22"
   ]
  },
  {
   "id": "duolingo-p17",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "AI-built courses",
   "statement": "Using generative AI, Duolingo launched 148 new language courses, more than doubling its catalogue.",
   "event_date": "2025-04",
   "date_precision": "month",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL10"
   ]
  },
  {
   "id": "duolingo-g22",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Luckin Coffee partnership",
   "statement": "Duolingo ran a Luckin Coffee partnership in China in 2025.",
   "event_date": "2025-11",
   "date_precision": "month",
   "evidence_kind": "documented_offer_or_action",
   "sources": [
    "DL11"
   ]
  },
  {
   "id": "duolingo-p18",
   "business": "Consumer language-learning app",
   "category": "product",
   "dimension": "Video Call to Super",
   "statement": "AI Video Call conversation practice moved into the cheaper Super tier as part of the 2026 plan.",
   "event_date": "2026-02-26",
   "date_precision": "day",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL23"
   ]
  },
  {
   "id": "duolingo-g23",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Growth over bookings",
   "statement": "The 2026 plan reduced friction in the free experience and gave up over $50 million of bookings to improve retention, targeting 100 million DAUs by 2028.",
   "event_date": "2026-02-26",
   "date_precision": "day",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL23"
   ]
  },
  {
   "id": "duolingo-g24",
   "business": "Consumer language-learning app",
   "category": "go_to_market",
   "dimension": "Creators and Streak Revival",
   "statement": "Creators supplied about two thirds of social impressions in key markets, and a June 2026 Streak Revival campaign brought back 15.4 million learners' streaks.",
   "event_date": "2026-08-05",
   "date_precision": "day",
   "evidence_kind": "company_described_offering",
   "sources": [
    "DL8"
   ]
  }
 ]
}