Tumblr’s David Karp Talks to Stephen Colbert About Porn, Profits and Mean Girls

Dropping out of high school, building a giant company from scratch, selling it to Yahoo for $1 billion-plus? No big deal.

Sitting down for a one-on-one with Stephen Colbert? “One of the scariest moments of my life,” David Karp wrote before his appearance last night.

But it worked out just fine! Colbert did put the Tumblr founder on his heels a few times — once when he asked him about the NSA, and again when he made a reference to “Heathers” — but Karp has always been a game and engaging interview. And well-prepared, too: Watch him mostly bat away Colbert’s inevitable porn question.

Oh! And Yahoo investors — in case you’re wondering whether Karp plans on kicking back now that he’s sold — he wants to reassure you: “I’ve got lots to prove. We’ve got to get this thing to profitability first. That’s a pretty big milestone.”