Marketers are finding extreme variances in their affiliate marketing programs, according to Internet Retailer. A study by Shawn Collins Consulting showed that response rates vary enormously from below one percent to more than five percent. In some ways this isn't surprising, as different types of marketers have quite different value propositions they can allow affiliates to make to audiences. The survey found that marketers believe email has been the most effective mechanism for recruiting affiliates, ahead of phone contacts and advertising in affiliate directories. Two out of five marketers offer a tiered affiliate commission system. Interestingly, 28 percent of marketers said that they had no problem with affiliates bidding on their brand names on search engines.