According to data released this morning ahead of Apple’s imminent earnings release, the relatively standard-sized iPhone 6 is outselling the 6 Plus phablet by a 6-to-1 margin.

But interestingly, iPhone 6 Plus owners are using apps more … and longer.

The iPhone 6 is being adopted at twice the rate of Apple’s previous flagship model, the 5s, mobile marketing firm Localytics says, and now makes up six percent of all iPhones on the market. That suggests serious pent-up demand. Its bigger brother, the 6 Plus, makes up one percent of all iPhones in current use. That’s also significant — just one month after release.

This compares to the iPhone 5c, released at the same time as the 5s, with just 9 percent of iPhone device share. The iPhone 5s currently makes up almost a third, 27 percent, of all active iPhone devices, and the older iPhone 4s now has an 18 percent share.

Localytics iphone_engagement

That bigger screen on the 6 Plus, however, is doing something tablet-like. Owners spend 13 percent longer in apps and open apps 11 percent more frequently on the big devices. Larger-screen devices, Localytics hypothesizes, lead to higher engagement.

This device share data comes from Localytics’ app analytics’ software, which is embedded in 28,000 apps on 1.5 billion devices. It’s not an exact proxy for sales, but with that level of penetration into the app and device universe, it’s not likely to be very far off.