I got around 300 Web 2.0 d0follow backlink source in my database, 70% .com others residential TLDs, everything is fine.
thats a lot, i have over 100, but havent used them for a while & as im going through them they have either been turned into paid models, or are not web 2.0 sites any more.
the paid models are obviously aimed at less informed people because for the same money or less you can get your own domain & hosting etc