The company's fourth-quarter retail online index report showed while smartphones generated the most traffic on mobile platforms -- almost double that from tablets -- the tables were turned when it came to actual sales, ZDNet reported Thursday.
Between Oct. 1 and Dec. 31, 21.3 percent of all online traffic was from smartphones, almost double the 12.8 percent coming from tablets.
But in terms of ringing online cash registers, tablet users accounted for 11.5 percent of all online sales, more than twice that of the 5 percent figures for smartphone users.
Online sales in total were up for the fourth quarter, with an increase of 10.3 percent over the same quarter the previous year, IBM said.
In the battle of mobile operating systems, smartphones running Apple's iOS generated e-commerce sales at five times the rate of Android devices, it said.