NEW YORK ( TheStreet) -- Cyber Monday online sales were up 20% over last year as of 12 p.m. EST, according to IBM Benchmark.

Most shopping is expected to come from laptops and PCs during the day, with mobile shopping activity picking up later this afternoon.

The number of consumers currently using a mobile device to visit a retailer's Web site is 13.3%, while 8.5% are using smartphones to make a purchase.

Online sales were the standout over the Thanksgiving weekend, with comScore reporting a 26% increase in sales to $816 million. This made Black Friday the heaviest spending day on the Internet so far in 2011.

- Reported by Jeanine Poggi in New York.

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