13.97% of all sales in January through the 10,000 affiliate sites of Affiliate Window were transacted on mobile devices, down from 14.72% in December, the U.K. affiliate network reports. 5.72% of sales stemmed from smartphones in January, down from 5.8% in December. 8.25% of sales came from tablets in January, down from 8.92% in December, Affiliate Window says.

19.63% of total traffic on the affiliate network in January was mobile, up from 19.04% in December, Affiliate Window reports. 11.32% of traffic came from smartphones in January, up from 11.11% in December. 8.31% of traffic stemmed from tablets in January, up from 7.93% in December, the network says.

Mobile traffic converted at a rate of 3.43% in January, down from 4.37% in December, Affiliate Window says. Smartphone traffic converted at 2.43% in January while tablet traffic converted at 4.64%, the affiliate network says.

The mobile commerce conversion rate dropped significantly in January because of the holiday boom in December, says Matt Swan, a client strategist at Affiliate Window.

“It was not just mobile devices that showed a drop off in conversion from the Christmas period. This was also seen across desktop, too,” Swan says. “The urgency to buy, with last delivery dates before Christmas approaching, means that we typically see vastly improved conversion rates in the run-up to Christmas. We would expect conversion rates to improve once again as more retailers are beginning to launch mobile-optimized sites.”

Even while mobile sales dropped after the holidays, mobile traffic increased. Affiliate Window predicts traffic will continue to grow at a robust pace throughout 2013.

“We could realistically be looking at around 30-40% of our traffic coming through mobile devices in a year’s time,” Swan says. “This will predominantly be driven by tablets as more consumers turn to these as an alternative to using a desktop. Handset traffic will also increase but advertisers need to understand the intention of this traffic. Visitors through handsets may be looking for directions to the nearest store or comparing offers when in store. Retailers need to be able to capitalise on this increase in traffic, and mobile will play an even more significant role in driving footfall to stores.”