If you are basing any of your marketing decisions based off of your Google Analytics stats, you may want to be aware of Referral Spam. This spam will throw off your Bounce Rate and will skew other analytical measurements. It basically makes your analytics data useless. Unfortunately, Google is not doing anything about it.
To see if you're being hit with Referral Spam, check out your analytics and click on "Acquisition", then click on "All Traffic", and then click on "Referrals". (Make sure you set your beginning date far enough back to see how long your stats have been getting skewed)
The word, based on various forums, is that Google does not use Google Analytics in its various algorithms to rank your website (A bad Bounce Rate is bad). I guess these Referral Sites are not really hitting your Web Page. They are just fooling Google Analytics that it did hit the website. Most of these Referral site are coming from Russia.
If you're currently running an Ad, Ad Words, and etc, make sure the sales person does not use this bad data to try to sell you more Ad time/etc.. (# of hits).
There are a few work-a-rounds (Filters), but they do not work that great and you will just get new Referral Spam from another address. You can google about Referral Spam problems and you will get a few helpful articles like this one, below, but nothing works 100% and does not take effect immediately. Google Article