Rafat Ali covers this story in detail. Fred Wilson and Alan Meckler both clamor that it's the victory of free ad-supported models over fees. I don't remember too many people making that claim 2-3 years ago when most ad-based web sites (including finance sites) were in a world of pain and rushing to transition to subscriptions. The reality is that ad markets are very cyclical and if you can combine ad revenue with user fees then you get the best of both worlds, provided you reach critical mass in both (easier said than done of course).