STEWART BUTTERFIELD

Co-founded Ludicorp in 2002 to build a multiplayer online game called "Game Neverending." The game failed, but the photo-sharing tool they built as a side feature became Flickr. Yahoo acquired Flickr in 2005 for approximately $25 million.

Left Yahoo and co-founded Tiny Speck to build another game — "Glitch." That game also failed, but the internal communication tool they'd built became Slack. Launched Slack in 2013 — it grew to 8,000 sign-ups on its first day and became the fastest-growing business application in history.

Slack reached 12 million daily active users and $900 million in annual recurring revenue. Salesforce acquired Slack in 2021 for $27.7 billion — one of the largest tech acquisitions ever.

Butterfield personally made approximately $1.5 billion from the Slack sale. Now invests in startups and real estate.

Known for his philosophical approach to technology and work.

Slack (co-founder, sold to Salesforce for $27.7B), Flickr (co-founder, sold to Yahoo), angel investor

Product-intuition investor. Butterfield invests in companies building tools that improve how people work and communicate.

His edge is taste — he has an exceptional sense for products that will become essential daily-use tools. As an angel investor, he focuses on SaaS, productivity, and communication platforms.

Not a volume investor — he picks carefully based on product quality.

Slack's $27.7 billion sale to Salesforce. Butterfield turned an internal chat tool from a failed video game into the defining enterprise communication platform of the 2010s.

The Salesforce deal was the largest SaaS acquisition at the time. But the deeper win is the Slack-to-billion-dollar pattern: both of his billion-dollar companies were accidental byproducts of failed games.

Flickr. While the $25 million sale to Yahoo was profitable, Yahoo subsequently mismanaged Flickr into irrelevance.

If Butterfield had held on and grown Flickr independently, it could have become Instagram (which sold for $1 billion in 2012 and is now worth far more). Selling too early to the wrong acquirer is his one clear regret.

The best products come from solving your own problems. Both Flickr and Slack were tools Butterfield's teams built for themselves.

His philosophy: if you're building something that you and your team actually need, the product-market fit is already there. "We didn't set out to build a chat tool.

We set out to build a game. But the chat tool was what actually worked."

Was married to Flickr co-founder Caterina Fake (divorced). Married to Jennifer Rubio (co-founder of Away luggage) since 2022.

Has two children. Born Daniel Stewart Butterfield in Lund, British Columbia — grew up on a commune without electricity or running water.

University of Victoria (BA in Philosophy), Cambridge University (MPhil in Philosophy of Mind). One of the few tech billionaires with a philosophy degree — and he credits it with shaping his product thinking.