It's Cyber Monday. Other than the dubious distinction of being the biggest online shopping day of the year — and the unofficial start of the online holiday shopping season — Cyber Monday is also known as the day when the world gets loads of data about how Americans spent their money over the four-day Thanksgiving holiday weekend.

Several sources have said that if the weekend numbers hold for the rest of the season, this will be a good holiday for retailers. And if early numbers are any indication, mobile devices will play a key role in consumer shopping behaviors. 

According to PayPal, Black Friday was the company's largest mobile shopping day ever. The company said it saw an increase of 193 percent over last year in mobile payment volume worldwide. Additionally, PayPal said it saw an increase of 173 percent in the number of customers shopping via mobile device on Black Friday. Houston saw the largest mobile payment volume, for PayPal, followed by Chicago, Los Angeles, Miami and New York.

In its annual Digital Analytics Benchmark report on holiday shopping, IBM also saw a nice increase in total spend on Black Friday and a surge in mobile shopping. Overall, shopping on Black Friday was up 20.7 percent over 2011, IBM said. And nearly a quarter of shoppers (24 percent) said they used a mobile device to visit a merchant's website. That's up from 14.3 percent last year. Sales through mobile devices were 16 percent of all sales; that's up from less than 10 percent last year.

IBM said that of all mobile devices, the iPad generated more sales than any other device, accounting for nearly 10 percent of online shopping. The iPhone made up 8.7 percent of online sales.

"This year's holiday shopper was hungry for great deals and retailers didn't disappoint, rolling out compelling offers which consumers gobbled up on Thanksgiving straight through Black Friday," said Jay Henderson, strategy director for IBM Smarter Commerce. "The big winners were chief marketing officers who used technology to deliver customer experiences that not only connected shoppers with personalized deals but did so at the right touchpoint and at precisely the right time and place, whether on their couch or the store floor."

Tonya Bradford, an assitant professor at Notre Dame's Mendoza School of Business, said that if retailers wish to remain relevant, they must find ways to participate in holiday rituals that help consumers' attain the holiday experiences they imagine — enjoying time with family and shopping when convenient. "Technology provides more opportunities for retailers to create these experiences for consumers through their mobile computing devices," she said.

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