I wouldn't say the value of TC is traffic, but more so an introduction to the VC/Tech community. TC posts so much each day that your post will be bumped off the front page in no time. However if just the right person is reading TC or picking up the feed, it can lead to good things for your startup.

Also, the posts that really seem to draw comments and the most buzz are all about the titans of the industry (Facebook, Yahoo, Google, MS) They don't exactly need the PR but that's what people love to discuss and rant about.