Funny story about 20 years ago I was at some party for I think EFF or PGP in sf, I had no idea what stumbleupon was and I met the ceo, it was already wildly successful and he described what it was to me and I was like "oh interesting idea, have you launched it yet" and he gave me the most confused look ... still remember it.

boom, jan 2007: https://www.eff.org/deeplinks/2007/01/effs-sweet-16-party-su...

Apparently there's a mitch kapoor connection between the two