I think that SpudMud.com is a bit of an anomalie, because me and my brother have done zero marketing for SpudMud and it seems to be booming. We started out with a few visits a day during the late Alpha stages which I was quite pleased with but now half way through the Beta stages me VPS is starting to struggle with all of the hits (and also my bad coding ) During on day 28/06/2007 – 29/06/2007 we had a massive spike in traffic of almost 1,600 unique visitors with a total of about 6,000 page views which was absolutely astonishing, this was all due to BowMan Battlefield being submitted to StumbleUpon and all this traffic seems to come at once at about 1PM GMT on both days.
Also over the past week (while I was on holiday) SpudMud has been getting 3000+ pageviews a day which is just amazing considering I have done zero marketing/advertising. I just hope that we can keep this going.

Also all of these stats are not the actual figures because I havent put any stats on the open in new window pages but will soon.