From my experience with Adsense I got disapproved after a visit from a URL to my blog. The URL was SPAM which is known as REFERRAL SPAM. See more about REFERRAL SPAM here. Why Adsense account got disapproved of Referral SPAM ? In the Google Adsense policies, It says that you should not pay someone to visit your blog/site. When you are placing the ad on your blog, Google tracks each visit to your blog. When they see a suspicious URL in the traffic sources they count it as a paid to click URL.... [READ MORE]