Duolingo, a Pittsburgh-based language learning company, has filed to go public.Luis von Ahn (inventor of CAPTCHA/reCAPTCHA) and Severin Hacker co-founded the 400-person company. The most interesting part of its story is: It's a way to monetize as an edtech consumer company based outside Silicon Valley. It has been a long and difficult journey to find the right business model. Despite initially being disinterested by subscriptions, the company eventually found the right business model.The S-1 shows that earlier decisions have led to a sharp increase in revenue at the company.Subscriptions make up the majority of Duolingos revenues. For example, 73% of the company's total revenue came from subscriptions in the most recent calendar year. Advertising incomes followed closely by the Duolingo English Test, which represented 17% of the company's top line in 2020. (Notably von Ahn had hoped that the DET would make up 20% of Duolingos revenues by 2019, but it was not able to achieve that figure by any means.The multi-part business model seems to be paying off. The company's revenue increased 129% from $70.8 million in 2019, to $161.7 millions in 2020. While some of this growth could have occurred without the recent pandemic in the world, it is easy to see COVID-related acceleration. Duolingo reported $55.4million in revenue for the first quarter 2021, which represents a 97% increase over the previous year.Recently, the company was able to turn a profit on an adjusted basis.Duolingo's net losses have increased in stricter accounting terms. For example, net losses for Duolingo in the three months ending March 31, 2021 were 13.5 million. This is a significant increase from the $2.2 million net loss it suffered last year. The company's GAAP net loss increased from $13.6 million up to $15.8million between 2019 and 2020.The net margin of the company improved in 2020 as its revenue more that doubled, and its losses barely climbed higher. During its impending listing, the company's profitability should not be an issue.Duolingo gave a placeholder figure of $100 million in its S-1 filing. We will get a better idea about how much capital the edtech unicorn might raise when it establishes an IPO price range following its roadshow.This former startup serves as the launch pad for the Q3 2021 IPO Season, which several inventors told TechCrunch would be more than just active.Duolingo has raised $183.3million in venture capital. NewView Capital, Union Square Ventures CapitalG, CapitalG and Kleiner Perkins are some of the investors that hold a meaningful stake in the company. General Atlantic recently received a spot at the cap table via a secondary transaction.Duolingo's privately-set $2.4 billion price tag should not be a problem at a run rate of approximately $220 million and growth of over 100%. Public-market investors should not be concerned about the slowdown in edtech market growth. These concerns could be tempered by Duolingo's nearly 100% growth in the first quarter.Factoids and other joyTechCrunch continues to comb through Duolingos IPO filing but has found a few details that will add some color to the company's recent growth. These are the highlights:The company had a record-low attrition rate of 2% in 2020, with only four employees leaving the company.Duolingo plans to eventually launch a Duolingo Proficiency score across all its languages. This will allow the company to create a globally accepted indicator of language proficiency and make Duolingo an international proficiency standard.Apple's Translate tool, an iOS application that lets users translate text sentences and speech between multiple languages, was cited by the company as a competitor under the risk factors section.It also confirmed that it is looking for potential acquisition candidates to enhance its startup's complementary services.Duolingo will list its company on the NASDAQ stock market using the ticker symbol DUOL.
