In mobile commerce, tablets are something of a mirror image of smartphones: Smartphones drive tons of traffic but offer low conversion rates while tablets do not drive nearly as much traffic but offer very healthy conversion rates, sometimes higher than desktop conversion rates.

What drives those healthy tablet conversion rates? Ask any retailer or research firm and they’ll say the same thing: iPads. Shoppers armed with Apple Inc. iPads, the crown jewel of tablets, buy lots more stuff (and do so more frequently) than shoppers on Android tablets, plain and simple.

Affiliate Window, which operates affiliate networks in the U.S. and U.K., shows this to be true for the 2014 holiday season in its new post-mortem of the period—just as it shows every month in its monthly analysis of mobile commerce, the company says.

In January 2014, about 75% of tablet clicks on Affiliate Window’s affiliate networks came from iPads while about 25% came from Android tablets, the company reports. However, in December 2014, during the holidays, that gap had shrunk to 60%/40%.

But. Mobile commerce sales via iPads accounted for 83% of sales on tablets in January 2014 and 74% in December 2014, Affiliate Window reports.

“Users of iPads are web savvy, wealthier and comfortable spending more and transacting frequently” compared with users of Android tablets, Affiliate Window says in a report on holiday commerce. “The proliferation of Android tablets, it could be said, is diluting the consistently strong performance of tablets. Users of iPads are shoring up the tablet’s reputation for delivering higher value sales.”

Follow Bill Siwicki, editor of the 2015 Internet Retailer Mobile 500 and editor, mobile, at Internet Retailer, at @IRmcommerce and at @MobileInsiderBS.