1 Okay, stupid question, but how is referrer spam even supposed to work?  Its not like email, where everyone checks it regularly ( or else there's no point in having email ).  One could run a server without ever bothering with the referrer logs.  So, how much money could the spammers possibly make putting spam in them?

2

Well, it's not well conceived. What they're relying on, I think, is sites with automatic trackback posting. I don't have that, though, so referer spam to my server is a complete waste of time.

The only other benefit it might have for them is that it might entice me, the owner of the site, to take a look at them to see how and why they linked to me (ha ha).

Most of these people are "script kiddies", using packages they've gotten from someone else who assured them that it would be tremendously effective.

3 I think the main attack vector for the referrer spam is through Web-based statistics packages such as Analog. Some people have them located at common URLs, unprotected, and Google indexes the results.