The explosive growth in mobile data traffic contributed to a 16.5 percent increase in overall Christmas Day sales, IBM has found, with smartphones and tablets accounting for nearly half of all e-commerce activity. That’s up from 28.3 percent in 2012, a jump that can be attributed to the rapid expansion of the Internet of Things and the subsequent rise in platform-agnostic experiences.

Nearly 29 percent of online sales came from mobile devices, representing a massive 40 percent increase compared to last year, according to the company’s report. But while smartphone users generated the lion’s share of the traffic to the 800 retail websites IBM surveyed, they made less than half as many purchases as tablet owners, who accounted for an impressive 19.2 percent of all sales. The latter group spent more as well, averaging $95.61 per order compared to $85.11.

Apple customers also have an edge over their peers: as a percentage of total online sales, iOS racked up more than five time as much as Android while generating more traffic (32.6 percent compared with 14.6 for Google’s operating system). Furthermore, orders from iPhones and iPads were twice as high as than the $48.10 average on Android, beating out social media-referred spending.

“Shoppers referred from Facebook averaged $72.01 per order, versus Pinterest referrals, which drove $86.83 per order. However, Facebook referrals converted sales at nearly four times the rate of Pinterest referrals, perhaps indicating stronger confidence in network recommendations,” IBM said.

IBM’s Christmas study echoes the trends outlined in its earlier report for Black Friday and Thanksgiving, which found mobile transactions reached 25.8 and 21.8 percent of total online sales, respectively. Overall, e-commerce grew 18.9 percent in the 2013 holiday season.