The Idea

In 2008, Jeff Atwood and Joel Spolsky were two programmers nursing the same annoyance. The go-to place for coding answers was Experts Exchange, a site that buried community-written solutions behind a paywall and made developers fight to read what other developers had given away for free. Both thought the model was backwards: knowledge built by a community should be free, fast, and ranked by that same community. So they built the opposite of Experts Exchange. A free, ad-supported Q&A site where the best answers rose to the top through voting and reputation points, and the worst sank. They launched in September 2008. Within a few years it was the single most important website on the internet for anyone who writes code, and the quiet engine behind a generation of software. This was the beginning of Stack Overflow.

The Execution

• 2008: Atwood and Spolsky launched Stack Overflow in September as a free, vote-ranked alternative to the paywalled Experts Exchange, reaching public beta within months.
• 2010: The company raised a $6 million round to expand beyond programming into the wider Stack Exchange network, which now spans over 170 Q&A sites.
• 2020: Locked-down developers flooded the site during COVID, pushing monthly questions to a peak near 300,000, the high-water mark for the forum.
• June 2021: Prosus acquired Stack Overflow for $1.8 billion, roughly 28x its then-revenue of about $65 million, one of the largest software-community deals on record.
• December 2022: ChatGPT launched. Trained in part on Stack Overflow's own archive, it gave developers instant answers without the forum, and traffic began falling off a cliff.
• October 2023: With Elon Musk having branded the situation "death by LLM" months earlier, Stack Overflow laid off nearly a third of its workforce, about 100 people.
• Spring 2024: Rather than fight the AI labs, it started selling to them, signing OverflowAPI data-licensing deals with Google for Gemini and OpenAI for ChatGPT, turning 17 years of vetted answers into a recurring revenue line.
• Today: The forum logged just 6,866 questions last month, roughly its 2008 launch volume, yet revenue has roughly doubled to $115 million, losses have shrunk from $84M to $22M, and enterprise product Stack Internal is now used by 25,000 companies.

The lesson?

Your traffic and your business are not the same thing. Stack Overflow lost the war for developer attention to the very models its own answers helped train, then doubled revenue by selling the one asset the AI labs could not generate themselves: a 17-year archive of human-vetted answers. The audience walked out the front door. The back catalogue paid the bills. When your moat is what you've already built, a dying front door doesn't have to mean a dying company.