I saw a post talking about Digg on Real Tech News, comparing it to slashdot. The comparisons seemed very apt to me:

Digg users do not click ads. Webmasters should stop trying to game the system to get the traffic. The increased traffic will use up your bandwidth and will risk slowing down or crashing your server. In the short run, getting on the front page is more likely to cost you money than make you money if you are depending on ads for your revenue

I know that getting Slashdotted can knock a site off the air; apparently, getting Dugg can now do the same thing.

Digg traffic does not generate new users, comments, or posts. Digg users often comment regarding a site on digg itself instead of on the dugg website. Even though we have often had easy ways for people to leave comments (no registration required), digg users typically do not post.

I can't say that I've ever been slashdotted (or dugg), but I have had traffic spurts from techmemorandum, or from links from popular bloggers. For the most part, this observation is correct - a brief spike doesn't tend to add many permanent new readers. After the last couple of these, I noticed a handful of new subscriptions on BlogLines, for instance.

Every site on the front page gets flamed in the comments. If you read digg, you need a thick skin. If the site is something about windows, the apple/linux people whine… and visa versa. However, this is in no way saying that the comments are not helpful to the digg users or to the webmasters.

That certainly sounds like Slashdot. Anyone who's ever had the patience to follow a thread over there knows that the comments devolve into a flamefest, quickly. It's especially bad when either Apple or Linux come in for criticism - constructive or otherwise.

Ultimately, sites like Slashdot and Digg do serve a purpose - they give you some notion (like techmemorandum) as to what part of the blogosphere is talking about. It's a limited chunk, to be sure, but it's still interesting. Just don't count on it for making you into an A-Lister.