According to the latest Mercent eCommerce Performance Index, same-seller GMV (gross merchandise volume) for retailers selling online through Mercent Retail rose 31.9% in the fourth quarter compared to the same period in 2008.

Mercent's index also showed that same-seller GMV for its clients participating in Amazon's "Selling on Amazon" program grew 78% in the fourth quarter compared to the fourth quarter of 2008.

Mercent attributed the sales growth across all online channels to strong consumer spending; the appeal of online channels that provide aggressive and competitive buying options to online shoppers; and the efficiencies of major online shopping destinations such as Amazon, eBay, Google Product Search, Microsoft Bing Cashback and others.

Mercent retailers include 1-800-Flowers, Bass Pro Shops, Brookstone, GUESS?, L'Occitane USA, Redcats Group and REI. The company helps clients sell on Amazon.com, eBay, comparison shopping engines such as Shopping.com and NexTag, affiliate marketing programs such as LinkShare and the Google Affiliate Network, and other product advertising channels including Microsoft Bing Cashback and Google Product Listing Ads.