Flickr's business model

Flickr is really popular, but I've always wondered how they planned to make money. Thanks to O'Reilly, here's their business model:

[O'Reilly editor Richard] Koman: So, what's the business model?

[Flickr CEO Stewart] Butterfield: There are two halves to it. The first is that things that are driven by individual users, so subscription fees for premium services. Actually, we're doing fantastically with that so far; we're really happy with the results. There are other things like printing, CD and DVD backups, and gifts--so if you take a bunch of photos at a wedding, you can pull them with friends and families photos and give them to the bride and groom. Those are probably secondary to subscription fees.

The other side is monetizing the whole collection of photos, essentially advertising. If you look at photos that are tagged with "Italy," you'll probably see ads for hotels in Italy, tours of Piedmont and whatever. There's a lot of contextual advertising you can do against big collections. And in addition, a bunch of different marketplace activities, allowing people to sell prints of their photos, letting people sell images to news media, and stuff like that. And probably all of those are secondary to advertising.