I'll give spammers this: they think of ways to spam people that haven't even occurred to me.
In case you don't know, web logs usually contain a link to the referring site -- i.e., if you clicked on a link on site A that takes you to site B, then the log for server B will show that that access came from site A. It's an interesting way to see how people are finding your web site.
Recently, though, I've been very puzzled by some of the referrers that have shown up in the web logs for mohea.com. I've started seeing more and more porn sites showing up in the logs. It seems reasonably safe to assume that none of these sites are really linking to our web site, so why the link? It was obviously spam, but what was the point? The server logs are private -- no one but Meredith or I ever see the logs.
But, of course, that's not always the case: a lot of web sites (and blogs) now include links to the most recent referrers to their site. So, by spamming the referrer logs, they get their porn sites to show up on other people's sites and blogs. To stop this, people are starting to develop referrer blacklists, similar to Jay Allen's MT-Blacklist that blacklists blog comment spam.
(You can read more about this phenomenon here.)
I really hate these people.