Web publishers are merging the two techniques as they jockey for top search engine placements. But ironically, advertisers compete for those placements with their affiliate Web publishers—meaning they need to decide if publishers are undermining their branding and search marketing efforts or providing a valuable service. With a growing number of advertisers offering cost-per-acquisition deals, publishers have begun to pay for placement to generate more advertising revenue.

One search marketing method publishers use is to purchase keywords on a specific advertiser or product, then direct traffic to their own site or promotional "mini-site," where they have placed affiliate marketing links alongside content to help make the sale. The affiliate marketing links then take visitors to the advertiser’s site.

Some search engines let publishers submit actual affiliate marketing text links that appear in the search results.

A second method is paying up front for visitors via pay-per-click search engines and attempting to earn revenue from any resulting performance-based sales or leads. Publishers can test different advertisers, links and keywords and determine the combinations with the highest potential ROI. Publishers then pre-sell an advertiser’s affiliate marketing link on the pay-per-click engine, pay for any clicks that result, and once a conversion takes place, earn revenue off the margin.

For advertisers, affiliate marketing has become a popular tool because it provides results on a pay-for-performance basis. But advertisers feel they’re in competition with their own publishers when those publishers also submit advertiser’s text ads to the search engines and bid on keywords associated with the advertiser’s brand.

Many publishers achieve higher placement in the search engines—promoting advertisers and their products—than the advertisers themselves. The result is that visitors who search for a specific advertiser online may receive a list of sites including the advertiser’s official site, along with several publishers’ sites promoting the advertiser.

One benefit to advertisers is that publishers test the advertiser’s keywords and advertising creative at their expense. Some advertisers divide their search marketing initiatives with their publishers. For example, the advertiser can focus on keywords and phrases using trademarked terms that most affect its brand, while allowing publishers to target specific products or categories for which the advertiser has provided creative.

For example, Mondy Beller, director of marketing at Shoes.com Inc. (which owns and operates sites for Famous Footwear, Shoes.com and The Walking Co.), says traffic from affiliate marketing usually converts at a higher ROI than traffic from its own pay-per-click keywords buys. Beller’s only requirement for search marketers is that they must link back to the appropriate advertiser Web site.

Among the search engines, Overture doesn’t permit affiliate marketing links in its listings but does allow publishers to submit links that direct users to a jump page on the publisher’s Web site that contains affiliate marketing links. Google’s search engine, which has indexed and paid listings, accepts affiliate marketing links as well as links to jump pages, but asks publishers using affiliate marketing links to identify them as such. Google also adds the word "affiliate" to the end of all publishers’ text listings.

Through these published policies, search engines are attempting to evolve alongside online marketing while retaining the trust and loyalty of their most precious commodity: visitors. Smart advertisers will change with the times and consider leaving at least part of driving sales to publishers highly focused on conversion.

Lisa Riolo is vice president of client development at Commission Junction Inc. in Santa Barbara, CA, a pay-for-performance advertising network. She has previously worked at Peet’s Coffee & Tea and Bank of America.