Mr. Zhou.

Wondering what happened to Turntable.fm's fast following, Xoogler-founded cousin, Rolling.fm? The social music site has been serving up errors for about two weeks; Tenka, the founders' previous startup, is also gone. Co-founder and chief product officer Tim Zhou, whose resume includes IBM and Google, did not respond to a request for comment by email, and now we know why.

It looks like Tumblr recently nabbed itself an Xoogler. Mr. Zhou created a Tumblr about one month ago and is now listed on the startup's staff page alongside 68 other employees (Tumblr, you're getting so big!)

We reached out to Mr. Zhou again this morning for comment. Our speculation? Rolling, a drastic pivot from deals provider Tenka, failed to raise money after being posted on AngelList (perhaps in part because no one wanted to compete against the golden child, Turntable).

Tumblr, meanwhile, is still hiring for eight open engineering positions as well as for Dutch and Swedish speaking ambassadors.