Cyber Monday, one of the busiest online commerce days of the year, is now extending to the rest of the holiday season. Consumers are no longer waiting until the Monday after Thanksgiving to surf the Web for deals. Rather, utilizing their tablets and smartphones, consumers are shopping online for a longer stretch. This is forcing companies like Amazon and eBay to compete with retailers to attract online buyers both before and after Cyber Monday.

“As more purchasing happens over the Web, e-commerce will keep outstripping shopping in brick-and-mortar stores,” reports Bloomberg. “Online holiday sales will increase as much as 15 percent to $82 billion, more than three times faster than the total gain of 3.9 percent to $602.1 billion, according to the National Retail Federation.”

“It now becomes more of a bell curve, where things start much sooner and end later,” said Steve Yankovich, vice president of innovation and new ventures at eBay. “It’s more fuzzy because we can shop so many more ways and have products fulfilled in more ways.”

Evidence of a longer buying period appeared last year, especially around Thanksgiving and Christmas. Growth in spending increased on those days — up 32 percent on Thanksgiving versus 18 percent in 2011. Meanwhile, Cyber Monday sales fell to 17 percent last year compared to 22 percent the year before.

This longer buying trend is expected to really take off this year with the increase in mobile offers. Purchases on tablets and smartphones grew twice as fast in the third quarter as desktop online spending, and for the first time in August, Web users spent more time engaging with retailers on mobile devices than desktops.

At present, one third of  average monthly traffic for lead retailers comes from smartphones and tablets. As a result, stores are offering more holiday deals that are available to consumers when they are utilizing these devices.

This year, Amazon began its Black Friday sale a day earlier than it did in 2012. They also offered new deals and gift ideas about every 10 minutes.

“EBay, owner of the world’s largest online marketplace, this month released a new version of its mobile-shopping RedLaser app,” explains Bloomberg. “The program from the San Jose, California-based company lets shoppers compare prices at a number of stores, including eBay’s own marketplace, putting its products in front of more consumers at the moment they’re ready to make a purchase. The newest iteration is equipped to push more coupons to consumers and discounts if they choose to shop on mobile.”

Meanwhile, Sears is offering more mobile promotions. Consumers with the mobile app can access e-coupons that are specifically customized to their tastes.

In spite of this growing online trend, Cyber Monday is still predicted to be the biggest e-commerce day of the year by companies such as eBay.