Zappos.com Inc. had the top-ranked customer service among e-commerce websites in a new study commissioned by customer service ratings agency StellaService.

The rankings are based on evaluations of more than 300 customer service features, metrics and policies for each site. The evaluation, which breaks the shopping experience into three sub-ratings – online tools, shipping and returns, and customer support – is aimed at monitoring every customer touch point throughout the online buying process. Those three sub-ratings are averaged to determine the final score.

Zappos, which received a score of 88 out of a possible 100 points, was one of 11 online retailers with a score of 80 or higher. StellaService considers a score of 80 or above elite; 75 to 79 and 75 very good; 70 to 74 good; 65 to 69 fair; 60 to 64 mediocre; and 59 and lower poor.

The other retailers scoring above 80 were:

    * Diapers.com, 87
    * Blue Nile Inc., 86
    * Staples Inc., 84
    * Amazon.com Inc., 84
    * L.L. Bean Inc., 82
    * Crutchfield Corp., 82
    * Sears Holding Corp., 81
    * Best Buy Co., 81
    * Apple Inc., 81
    * Recreational Equipment Inc., 80

The survey found that consumers would pay an even higher premium of 10.7% for excellent service at e-commerce sites.

The survey of 304 consumers was conducted by Greenfield Online and developed by Ovum, part of the Datamonitor Group.