In the logs of my website, there's a lot of visits with a HTTP referer set to spam-like websites (usually Russian sites, I've noticed). I assume what they're doing is just using a web crawler to visit any site they find with the HTTP referer as their site's URL.
Not only is this annoying because it skews stats regarding how many visitors I get, I really can't see what they hope to achieve either. That, on the rare occasion that I go crawling through my logs, I see a referer set to "spammyrussiansite.ru", and decide to visit it? There's more effective ways of spamming your site's URL than that, no?