what does an api have to do with profit making? are you encouraging closed source api's?
im not sure what that would solve.
If you recall facebook originally didn't want the un-washed masses on it's social network and found itself opening up to the world since that decision obviously wasn't growing the service.
I don't use facebook since I am one of those un-washed masses and now that it's ok for me to join they can kiss my rearend.
If it's anything like myspace they have advertising programs built in. All an API is suppose to do is bring the people to you, it's not to do anything else.
I think that all the hype about social networks doesn't mean payola and that's the moral of the story. If you took a cross section of people from these sites (we've already seen how myspace failed) you would probably be surprised how useless the service is.
Facebook never was a win, facebook will never be a win. They had their plan when the service started that the educated masses would lead to more profit for them and that logic died on the table. Now perhaps eddie the farmers facebook will bring in the $.
Nothing against people with real jobs, facebook sucks.