When comparison shopping is as convenient as opening multiple browser tabs, and payment is as simple as using a credit card, it’s no wonder online shopping continues to grow in popularity as retail store sales decline.

Surveys commissioned by the U.S. National Retail Federation predict all-but-stagnant growth in store sales this month and next. But online sales are expected to rise by as much as 12 per cent — (US)$44 billion — over the same period last year according to a recent Forester Research study.

U.S. retailers attempted to kick-start the Christmas shopping season this fall by kicking off their annual holiday sales more than a month earlier than usual. The unofficial start of the holiday shopping season came in early October rather than the day after U.S. Thanksgiving, in late November.

But Online retailers aren’t siting back waiting for the stampede to their virtual doors. Shop.org’s 2008 eHoliday Study reveals that almost half of online retail sites surveyed have improved their site search systems and added product videos in anticipation of the holiday shopping season. A third are also publishing customer reviews of products to augment their own basic product descriptions.

Of course, shipping costs are a concern. Online retail watchers say shoppers will likely gravitate toward sites which offer free shipping or wil bundle their purchases to save on shipping costs.