iPad tablet users are the most active user group throughout the day in North America, but Microsoft Surface users generate a bit higher share of total Web traffic during work hours. Those are key takeaways from a new report on tablet usage.

The report, "Tablet Hourly Usage Study: iPad Dominates, Surface Users More Active During Working Hours," was issued Wednesday by ad network Relevant Products/Services Chitika. It's based on online ad impressions from that company's network over a two-week period in late January and early February, based on 300,000 Web sites.

According to Chitika's data Relevant Products/Services, iPad users "are far and away the most active tablet user group" in raw volume during work hours as well as throughout the day. The peak hour for all tablet Web usage is actually 9 p.m. ET, and at that time iPad usage is four times that of Android tablets.

None Peak During Working

None of the three tablet groups -- iPad, Android or Surface -- reaches its volume peak during working hours, but Surface RT and Surface 2 users generated a slightly greater share of all the tablets' daily traffic during the hours of 12 p.m. to 5 p.m. ET.

iPad and Android tablet users seem more alike than not. The report noted that none of the differences between the two groups was greater than 6 percent at any given time, and the differences average to zero over 24 hours. The biggest difference: iPad users employ their tablets more during traditional morning commute hours than Android users, by a few points.

The report said that "the results support the idea that Microsoft's tablets are generally used more frequently during working hours as compared to its major competitors in the space." It also said that, since Android users are not that far behind iPad users, it appears that many Android tablets have "largely caught up with iPad in terms of functionality and other factors."

'A Lot of Appeal'

Microsoft has positioned its Windows Surface line as being more work-capable because of an attachable keyboard and Microsoft Office. The report, however, only measures ARM-based Surface tablets, meaning the RT and Surface 2, which run the limited Windows RT, but not the x86-based Surface Pro, which runs the full Windows 8. But, from Microsoft's point-of-view, the data offers promising news, since the differentiation of Surface tablets has been based in large part on their orientation toward productivity.

Ross Rubin, principal analyst for industry research firm Reticle Research, attributed the higher usage by iPad users in part to "the greater range of apps that are optimized for an online touch experience."

Even though the report only measured ARM-based Surfaces, he told us there is "certainly a lot of appeal of the two roles for the Surface, both as the normal tablet role of content consumption and as assuming some of the PC's role in productivity."

Chitika data cannot discern between different kinds of user activity, such as whether users are checking e-mail, watching videos, using a word processor Relevant Products/Services or playing a game. Additionally, Chitika does not measure unique users.