So you think that the higher up the search chain you go the better off your business is? Don't think so. Try this; bid yourself a way up into first place on your placements and just watch the fraudulent clicks go through the roof. You will get more false referrals in a week than you get in a year.
Ever hear of angelmature.com? no? That's because it and thousands of sites like them aren't sites at all; they're parked and they're used to generate click-throughs on ads that the advertiser pays for and they collect for. In other words, the advertiser ends up paying real dollars for thousand of fraudulent click-throughs, while the sites rake in a fortune in adword money. They probably even pay people to sit there and click through on their sites to generate their own income.
What else will happen? You'll see these click-throughs show up as visits to your site with a zero time on site and a 100% bounce rate - what more proof of fraud do you need? And how do you think they pick their targets? Number ones in the search list. Easier to hide their tracks that way, lost in the traffic. Unless you know what to look for, how to identify it and how to stop it, you will be paying someone to sit on their yacht in sunny old Antigua and laugh in your face.