For anyone operating a blog through Blogger, Wordpress or other server, there is an issue with spam referral sites. Basically, these are blank web pages which hook onto a blog or particular posts on a blog for whatever reason. One effect is that the stats for visits to a blog, such as this one, can be distorted. The page views for this blog are updated daily and overwhelmingly are real views, but the spam referral sites can constitute about 1% at any given time. Because specific posts are hooked onto, the facility to see "Popular Posts" has been taken down from this blog, as it is misleading.
If you have a blog yourself and you see referrals from sites, usually with a www3 or www4 prefix, ignore them and do not click on them. They are harmless but might not be if clicked on. They are annoying and that's all.