Here's Tumblr's CEO, David Karp, talking to the LA Times in 2010:
We're pretty opposed to advertising," Karp said this week in an interview at the company's Park Avenue office. "It really turns our stomachs."
And then here he is again, a week ago, talking to Ad Age:
Our attitude toward all this attention on Tumblr, which we could very easily throw a Google Adsense on and be profitable tomorrow -- that's so far down the list, I mean, we're selling our desks to avoid that, it's a complete last resort.
Aaaaaaand then here he is at the Ad Age Digital Conference yesterday:
I was probably being an idiot then.
So Tumblr is getting ads! They're not going to be in-your-stream ads like Twitter is experimenting with, or text-block advertising like Google AdWords. Tumblr is renting out a relatively new site feature, the Tumblr Radar block on the right hand side of your dashboard, for sponsored content. (See above.)
This was inevitable, of course — Tumblr is a ridiculously ripe platform for advertising, and the company just got $85 million in fresh cash from investors late last year. It's worth remembering that sometimes CEOs just say things that make them feel good. Advertising probably still turns Karp's stomach! Just not as much as the thought of losing Tumblr, or the prospect of making money. Next up: Instagram.