NEW YORK (TheStreet) -- Online sales jumped 24.3% on Black Friday compared with a year earlier, according to a study by IBM's (IBM) - Get Report Coremetrics data unit.

Early sales prompted more consumers to shop online on Thanksgiving Day, too, causing online sales to surge 39.3% year over year on Thursday, the study said.

"This year marked Thanksgiving's emergence as the first big spending day of the 2011 holiday season with a record number of consumers shifting their focus from turkey to tablets and the search for the best deals," said John Squire, chief strategy officer of IBM Smarter Commerce. "This momentum continued into Black Friday where the big winners were those retailers that delivered a smarter commerce experience with compelling, relevant deals that people could easily access from their channel of choice."


Coremetrics study

relies on real-time sales data from the Web sites of more than 500 U.S. retailers.

It found that more people are doing their research -- for both in-store and online purchases -- on mobile devices. Mobile traffic increased to 14.3% of all online retail traffic on Black Friday, vs. 5.6% a year earlier.

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Sales on mobile devices also surged, accounting for 9.8% of all online purchases on Black Friday, compared with 3.2% a year before.


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devices led the mobile shopping charge, with the iPhone and iPad ranking first and second, respectively, with 5.4% and 4.8% of total online retail traffic, the study said. Devices using


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Android operating system accounted for 4.1% of total traffic.

The study also found that shoppers using the iPad to visit retail sites were more likely to make a purchase than those using other devices.

Brick-and-mortar stores more than held their own against online-only competitors such as

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in online sales, the study showed, as department stores' online sales jumped 59% year over year.

On Friday, research from Comscore

also pointed to a significant increase

in Black Friday online sales, although it wasn't as big as that in the Coremetrics study.

This article was written by a staff member of TheStreet.