I don't think the spammers are targeting Google Analytics specificaly as much as they are trying to get links for their domains on to the internet. Lots of web

I don't think the spammers are targeting Google Analytics specificaly as much as they are trying to get links for their domains on to the internet. Lots of websites posts their visitor logs or stats on a special status-page (or at least used to do). If those links aren't rel=nofollow, then congratulations, your referer-spamming just gained yourself some SEO-bonus.