Quick note - it looks like About is profitable (50M) it seems like one of the most profitable arms of NYTimes model. Can't find specifics on HowStuffWorks yet. Pet Holdings I like, but is it profitable? Hulu the jury is out, they're just cash flow positive - but they just moved to a pay model. I actually categorize last.fm and hulu slightly differently in my head then the pure, text based web plays, but that's okay.

Demand media I was going to actually use as a counter example since they're not yet profitable (http://blogs.wsj.com/digits/2010/08/12/where-did-demand-medi...)

Last.fm was "hoping" for profitability this year (http://paidcontent.co.uk/article/419-interview-cbs-thinks-la...)

Well you counted Facebook as a big success in terms of advertising, but they aren't exactly raking in cash. To me that puts it similar to Hulu and Demand--making significant revenue, but the real money comes from an IPO.

For the most part we're not talking public companies, so it's hard to be completely accurate. But I think it's safe to say that there are a lot of online advertising funded businesses who are providing strong returns to their partners/investors.