Retailers had very happy holidays.

US retail e-commerce sales (excluding travel) for the fourth quarter of 2006 were the highest they have been in four years, according to the US Census Bureau.

On an unadjusted basis, sales totaled $33.9 billion, up about a third from the third quarter of 2006.

The Q4 2006 e-commerce estimate increased 25.0% from a year earlier while total retail sales increased 4.0% in the same period. E-commerce sales in Q4 2006 accounted for 3.3% of total sales.

eMarketer senior analyst and e-commerce specialist Jeffrey Grau said that the disparity between e-commerce and total retail sales is significant.

"Retail e-commerce sales for Q4 2006 exceeded expectations by increasing 25% over the same quarter a year ago," said Mr. Grau. "This is the biggest jump in Q4 sales since 2002 and is additional evidence that the Internet channel is stealing sales away from retail stores."

Total e-commerce sales for 2006 were estimated at $108.7 billion, an increase of 23.5% from 2005. Total retail sales in 2006 increased 5.8% from 2005. E-commerce sales accounted for 2.8% of total sales in 2006, and 2.4% of total sales in 2005.

Overall retail holiday sales are by no means shrinking, having grown each of the past four years, according to eMarketer calculations of Census Bureau data.

Online retail sales have always been small fraction of overall retail sales, but if growth rates hold steady, offline-only retailers may no longer be able to ignore the online retail share.

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