Chase Paymentech, which describes itself as the world's largest merchant acquirer, today said online retailers continue to see growth in both the number of U.S. transactions and sales volume as the Christmas shopping season is heading into its most important phase.

On average, sales are up about 30% over 2006, according to Chase Paymentech. Interestingly, Cyber Monday, estimated to have resulted in sales of $104.8 million for the 10 retail Web sites tracked by the Chase Paymentech Pulse Index, which is substantially less than the sum that was recorded on Wednesday, November 28 – which has been the most active online shopping day so far at  $134 million in sales and 2.1 million transactions.  

The tracking firm expects December 18 – 20 to exceed the November 28 volume and become the heaviest online shopping days during this season. Chase Paymentech said that Tuesdays and Wednesdays in general have turned out to be the most popular shopping days for U.S. consumers.