comScore has recently conducted a study on the relationship between paid search marketing (pay per click advertising) and retail e-commerce. The study, based on the March, 2007 comScore qSearch Marketer report, revealed that e-commerce web sites are the most frequent users of Pay Per Click (PPC) search engine marketing; each of the top ten search engine marketers were either retail or comparison shopping web sites.

According to comScore’s data, close to 20 billion sponsored links were served up to internet users in the United States. eBay was apparently the top search engine marketer—they had 802 million sponsored link “exposures” during the period. In March, 2007, the top ten paid search PPC advertisers were either retail or comparison shopping web sites. They made up sixteen percent of all sponsored links. eBay, as previously mentioned, was the top advertiser, followed by Smarter.com with 366 million (1.9 percent), and Shopping.com with 357 million (1.8 percent).

Top Sites Generating Search Engine Sponsored Link Exposures

March 2007

Source: comScore qSearch, Share of Voice Report

                  Sponsored Link          Share of
                  Exposures (000)      Sponsored Link
                                          Exposures

Total Internet        19,762,951           100.0%
eBay.com                 801,744             4.1%
Smarter.com              365,766             1.9%
Shopping.com             357,012             1.8%
Bizrate.com              297,649             1.5%
Amazon.com               284,328             1.4%
Dealtime.com             283,574             1.4%
Shopzilla.com            245,398             1.2%
Target.com               202,482             1.0%
Nextag.com               163,220             0.8%
Shop.com                 123,009             0.6%

comScore also looked at the referral activity by the top search engines in directing click-thrus to retail sites. Google’s web search accounted for 57.3 percent of all click-thrus and directed 53.8 percent of the click-thrus to retail web sites.

In comparison, Yahoo!’s web search directed 27.2 percent of click-thrus to retail web sites, followed by MSN Web Search (10.4 percent), AOL Search (5.8 percent), and Ask.com (1.6 percent).