Someone featured on GigaOm a few months back put together some data around the "Digg effect" and stickiness/surge in traffic a post on the front page. (Can't get the link now since I'm on my bberry, but it's around).

Also, I agree with Ryan regarding the type of audience one wants to reach. For me, TM is my first source for news in the morning because whatever is listed there is important, and therefore valuable.

Up and coming tech bloggers like Louis Gray or Corvida can gain targeted audiences because of TM.