eMarketer: Key trends to watch this holiday season

New York -Total retail sales in the United States will rise 5% to reach $862 billion during November and December this year, according to the latest forecast from eMarketer. Among the biggest trends to watch will be the acceleration in online sales, which are expected to grow at 16.6% year over year to reach $72.41 billion, or 8.4% of all retail purchases this holiday season. It’s a considerable uptick from 2013, when online sales totaled 7.6% of all holiday retail purchases.

What's more notable, according to eMarketer, is that retail ecommerce throughout the rest of the year will only account for 6% of total retail sales. Retail sales overall in November and December will comprise 18.3% of all retail sales for 2014, but retail ecommerce sales during the holiday season will have 23.7% share -- in other words, nearly one-quarter of the year's ecommerce sales will happen during just one-sixth of the year.

Two factors contribute to the outsized role of ecommerce in the holiday season, according to eMarketer. During the holidays, people look for presents in traditionally strong ecommerce sectors, such as consumer electronics, books and media but keep spending in staples such as pharmaceuticals and packaged goods relatively steady.

Second, shoppers tend to do their most intensive shopping of the year during the holidays, leaving them open to try new sites and new techniques.

Here are other key trends to watch this holiday season:

Mobile Commerce: In 2014, eMarketer predicts that retail sales on tablets and smartphones will reach $58 billion, 19% of all ecommerce sales, but just 1.2% of total retail sales.

In-Store Pick-Up: "Brick-and-mortar retailers love this option, because it saves them money and save shoppers time," said eMarketer analyst Yory Wurmser. "And since it encourages shoppers to come into stores it increases sales. In 2014's short holiday season, shoppers have an added incentive to use the option to reserve a purchase or eliminate the wait for shipping as Christmas sneaks up."

Mobile payments at the point of sale: eMarketer projects that mobile proximity payments will reach $3.5 billion this year, more than doubling last year's total. But when compared to the $800 billion to be spent in stores just this holiday season, it's clearly still small potatoes.

Beacons: "Most major retailers are experimenting with beacons this holiday season," said Wurmser. "The effect on sales will still be minimal, but consumers will see local messaging more often and in more ways this season as tests grow more ambitious."