Affiliates were among the earliest adopters of pay-per-click advertising when the first PPC search engines like Goto.com (which became later Overture.com, acquired by Yahoo! in 2003) emerged during the end of the nineteen-nineties. Later in 2000 Google launched their PPC service AdWords which is responsible for the wide spread use and acceptance of PPC as an advertising channel. More and more merchants engaged in PPC advertising, either directly or via a search marketing agency and realized that this space was already well occupied by their affiliates. Although this fact alone did create channel conflicts and hot debate between advertisers and affiliates, the biggest issue was the bidding on advertisers names, brands and trademarks by some affiliates. A larger number of advertisers started to adjust their affiliate program terms to prohibit their affiliates from bidding on those type of keywords. Some advertisers however did and still do embrace this behavior of their affiliates and allow them, even encourage them, to bid an any term they like, including the advertisers trademarks.