• by Chuck Martin , Staff Writer, January 13, 2016

The impact of mobile on this past holiday shopping season was projected to be huge, and huge it was.

With final tallies coming in, spending via smartphone for online purchases hit $13 billion, based on a new study.

That’s an increase of 59% from a year ago, according to comScore, and that’s just for the last two months of last year.

For context, $56 billion was spent online on desktop computers, but that was an increase of only 6% from last year.

Mobile accounted for 18% of all online commerce, compared to 13% a year ago.

Aside from the percentages, the dollar amount moving through mobile is significant. And that smartphone spending exceeded earlier estimates by $1 billion.

It also appears that retailers are taking note of the significance of mobile, finding that smartphones now lead tablets as a percentage of both online sales and traffic, according to a different study.

Retailers say that smartphone sales accounted for 17% of the total of their online sales last year, according to the State of Retailing Online study, which is based on a survey of 195 companies conducted by Forrester Research for Shop.org, a division of the National Retail Federation.

Sales from smartphones grew 53% from the previous years, according to Forrester.

Despite the obvious growth in smartphone activity, retailers continue to keep their mobile investments at a moderate level.

Almost a third (30%) say they invested less than $10,000 on smartphone platforms last year, and 17% kept budgets between $10,000 and $50,000. A number (18%) of retailers left smartphones out of their investment plans for last year.

However, it does appear retailers will be investing more in mobile going forward.

The survey found that a third of retailers plan to increase their smartphone investments more than 20% this year and another third (34%) say will increase spending up to 20%.

For tablets, which are now less significant than smartphones, one in five (22%) retailers plan to increase their investments more than 20% this year.

Of course, some of the tablet activity involves in-store personnel using the devices to assist in selling. In more than a third (36%) of retailers where mobile devices are used in stores, a quarter of those use tablets, which makes total sense, based on the larger screen.

Two in five (44%) of retailers say their sales associates use tablets to show additional products not available in stores and 40% use them to send receipts to customers.

Almost a quarter (23%) use tablets to check inventory in warehouses and 21% to check their actual in-store inventory. This is consistent with research that shows in-store shoppers want to know if what they’re shopping for is in stock.

Even though most actual retail transactions still happen in a physical store, no matter where consumers are shopping, their smartphone is increasingly part of the mix.

One way or another, the money at retail increasingly flows through mobile.