The IBM Coremetrics Benchmark shows that online sales rose sharply on Christmas Day as well as on the day after Christmas. Dubbed “Mega-Monday” by many retailers because Dec. 26 fell on Monday this year, IBM officials said online sales grew 27.8 percent over Dec. 26, 2010 levels.

Moreover, mobile traffic rose significantly. IBM said 16.4 percent of all online sessions on retailers' sites were initiated from a mobile device on Dec. 26, up from 7.8 percent on this day in 2010. Sales from mobile devices grew 164.9 percent from the same period in 2010 – from 4.3 percent in 2010 for Dec. 26, 2010, to 11.3 percent in 2011.

The iPad led all mobile-device traffic, at 6 percent on Dec. 26, 2011, followed by iPhone, at 5.8 percent, and Android, at 4.6 percent.

The IBM Coremetrics Benchmark tracks more than 1 million transactions a day, analyzing terabytes of raw, real-time data from 500 retailers nationwide.

For Christmas Day, IBM officials said online sales grew 27.8 percent over Dec. 26,
2010 levels. Online sales were 16.4 percent higher than on Christmas Day 2010, IBM said. Mobile devices accounted for 18.3 percent of all online sessions on retailers' sites, up from 8.4 percent on Christmas Day 2010. Sales from mobile devices reached 14.4 percent, compared with 5.3 percent on Christmas Day 2010. The iPad led all Christmas Day 2011 mobile-device traffic at 7 percent, followed by iPhone at 6.4 percent and Android at 5 percent.

IBM's Christmastime online sales figures follow the company's benchmark results for Black Friday and Cyber-Monday, which showed strong online sales on Thanksgiving leading to strong sales for Black Friday and Cyber-Monday.