The idea was that you could combine all your social media news streams (fb, twitter usw..) into one stream (just like a rss reader). It never got above a few users, and i did not have any ads or anything in place. Still use it myself though...
I make between $500 und $100 per month off my stand-alone cross-browser testing tool:
http://www.browseemall.com
The product was launched on february this year and it's growing nicely so far. Not real recurring yet, as every sale comes with one year of free updates.