Ok, I have known about blogarate.com for sometime now but have never really put any of these into action. "These" refer to del.i.cio.us, twitter, digg and so on. Now, the mind boggling thing to me is that how does these 24 x 7 companies generate revenue. They can't all be targeting for online advertisers and they need to generate substantial revenue in order to maintain their sites. Any comments on this?