Online sales 26 percent higher this year

By all accounts, sales growth has been strong. Excluding travel and auctions, consumers spent $21.7 billion at U.S. online stores between November 1 and December 20, a 26 percent increase over the same period last year, according to comScore Networks.

Even more significant, the spending increase between December 18 and December 20 was 35 percent, reversing a trend from past years when sales slowed down as Christmas Day approached. The change this year is due to retailers' improved ability to ship items on time later in the season and to consumers' willingness to pay extra for this convenience, according to comScore.

This conclusion is supported by a Shop.org survey publicized this month that found that the number of retailers guaranteeing that standard-shipping orders placed by December 18 or 19 will be delivered by Christmas Day nearly doubled from last year. This is a clear sign that e-tailers' supply chains have improved with IT, said Jeffrey Grau, a senior analyst at eMarketer. "They have become more efficient in the operations," Grau said.