Swimsuits and flip flops might be flying off virtual shelves now, but the 2014 holiday shopping season is not that far away. And, like 2013, it’s short. Last year, there were just 25 days between Black Friday and Christmas; this year, there are 26. In 2012, there were 31.

E-retailers struggled with the short holiday shopping season in 2013, and many missed holiday deliveries.

With that in mind, IBM releases its annual Online Retail Holiday Readiness Report. The report looks at holiday shopping trends from 2013 and aims to predict trends for the 2014 holiday shopping season.

The trend for the past two years has been for shoppers to spend more online during the holiday season. They spent on average 9.3% more per online order in November 2013 than two years earlier, and 13.0% more per order in December. In 2011, consumers spent an average of $121.38 in November and $108.39 in December. In 2013, those figures jumped to $132.71 and $122.46.

“In terms of online spending, increases in AOV and items per order suggest retailers are savvier than ever when it comes to delivering a streamlined online shopping experience—making it easy for consumers to find items and providing an enticing brand experience,” the report says. “To capitalize on this trend, heading into the holidays, retailers will need to rely on personalization and cross-sell recommendations to further strengthen customer relationships and wallets.”

While consumer spending is on the rise, consumer attention spans are on the decline, several metrics suggest. The average time on site sunk in September 2013 sank to 7 minutes and 9 seconds—a full second less than the time on site recorded in September 2011, and a new low for recent years as measured by IBM?. During the 2013 holiday season, the average time on site rose to 7 minutes, 40 seconds. Page views per session also hit a new bottom of 6.93 in March 2014. And the bounce rate—the percentage of site visitors who leave after viewing just one page—rose to 34.5% in October 2013, a new high, and well above the 28% to 29% rate seen in 2011. “Ultimately, shoppers have little tolerance for poor customer experiences—if they can’t find what they need, they’re moving on,” the report says.

The report attributes some of change in consumer behavior to the rise of consumers using mobiles devices for shopping. Sales on smartphones and tablets reached a high of 19.1% of all e-commerce sales in December 2013, up three-fold from December 2011. Mobile site traffic reached 38.2% in March 2014, more than double the percentage in March 2012. IBM estimates that 20% of site sales and more than 43% of site traffic will come from mobile devices in November 2014. “To succeed this holiday season, retailers will need to pay attention to both device type and operating system, to better focus their mobile app and analytics investments, while at the same time ensuring a flawless customer experience between devices and operating systems,” IBM says.