Since the emergence of affiliate marketing, there has been little control over affiliate activity. Unscrupulous affiliates have used spam, false advertising, forced clicks (to get tracking cookies set on users' computers), adware, and other methods to drive traffic to their sponsors. Although many affiliate programs have terms of service that contain rules against spam, this marketing method has historically proven to attract abuse from spammers.
VigLink works a bit differently than other affiliate programs in that it is specifically designed for bloggers. Instead of affiliates picking and choosing which merchants to work with, VigLink uses dynamic links that automatically change to work with merchants that VigLink has determined are offering the highest conversation rates and/or commissions at any given moment.