> Another thing I'm always looking for is tails that could wag the dog. The history of startups is full of these. Paypal started out doing security for hand-held devices. They created Paypal as a demo of their security software. But then eBay sellers started using it to take payments, and after a couple months the founders acknowledged that this was the business they were now in, even though they hadn't meant to be. So whenever founders build something peripheral to the main product I always ask: could this be the real product?

Reminds me of Slack. https://techcrunch.com/2019/05/30/the-slack-origin-story/

I never understood why anybody would pay for Slack when its based on IRC and IRC is free, but whatever. I guess when you are spending other people's money and all your employees are super insecure these kinds of things pay for themselves... maybe?