Strange Spam, any ideas?

Hey, just wanted to pick the collective brains of this fine community:

Received a couple of bits of spam on my blog, but the only link they've added is to Google or Yahoo. I've run a search, and it's definitely spam, since it appears on loads of sites!

My question is.... WHY?
Are they pointing at fake versions of the page? Is it just a test run to find AA blogs? Any ideas?

They're probably testing to find AA blogs.

The most common method is using a random address but I've seen people use Google/Yahoo as well.

I sometimes use G0ogl/Yahoo link to test AA blogs so it's me please forgive me

Again the same question ? use the search.

People do this to find auto aprove blogs.

I was just wondering

(It'd be much better if you linked to a fake Google/Yahoo page that automatically made itself your homepage, be quite a nice little earner )