Why do I sometimes get pingbacks from sites that never linked to me?

My website The Prize Blog will sometimes get a pinkback or refferal link from a site that has seemingly never linked to my site. Why?

Why do I sometimes get pingbacks from sites that never linked to me?
They are testing your site to see if it shows referrers on one of its pages. If so, you will get a huge number of bogus referrals from porn sites, etc.





Why would they do this? It is because if you show your referrers and they get their site on your page, their PageRank goes up in Google searches. This is sometimes known as "Googlespamming."