Referral spam is when a website sends lots of bogus traffic to your site in order to show up in your site analytics. They hope that you are excited and want to see the site that is sending you tons of new traffic, so you click through to the referrer website.
This type of spam is a major nuisance for a couple reasons. First, it messes up your analytics so that it becomes difficult to tell how well you’re really doing. Second, it uses hosting and services resources. I hit my traffic limit on Woopra (a live stats system) during the last billing cycle because of the spam.
Read MoreIdeally, I’d like to see analytics services (including Google Analytics) create an easy way to delete a referrer and all of its data (including page views, time on site, etc) from your analytics. A simple (-) link next to each referrer would be a big help...