[joeax]

Digg, Delicious, Mixx - lost to reddit

Plaxo - lost to LinkedIn

Bebo - social media space became too crowded

Geocities - died of natural causes

Netscape - slow to adopt after v3

[Grue3]

Digg lost because it moved too suddenly. I was bigger than Reddit, but Digg v4 pissed off all the users due to massive changes in site's operation.

[joshu]

Delicious was a different product from Digg or Reddit, so that doesn't make sense.

[yoklov]

And Digg lost for several reasons, but one of them wasn't that it moved too slow. More the opposite, really. They released a buggy version too soon, when the users were already angry and considering leaving.

[dagw]

Yup. Digg should be the poster child for why "move fast and break things" isn't always the best of ideas.

[oniony]

And Delicious still limps on. I still use it for bookmark management (read: bookmark stuff I'll probably never read again).