A large percentage of traffic that the Random* sites get is from people on Twitter, Jaiku, Pownce saying "hey my post was on randomtweets.com" (or Random Pownce or Random Jaikus).However, occasionally we (me and the sites) get links and reviews from other sources.
WebAware recently did a good review of PownceMeme.com and RandomPownce.com got a "See Also". I'll take a back seat to Bryan's Powce Meme any day.
A few weeks ago the OpenGiga and Snibbles blogs made posts about Random* sites. The Snibbles post was about RandomTweets.com and the OpenGiga post talked about all four sites.
