Another month has gone by, so it's time for another peek at Windows Phone usage, courtesy of my good friends at AdDuplex. This month, there are few surprises: Low-end Lumia handsets continue to dominate and high-end handsets continue to lag.

As you may remember, AdDuplex bills itself as the largest cross-promotion network for Windows Phone and Windows 8 apps, empowering developers and publishers to promote their apps for free by helping each other. And each month it provides a tantalizing glimpse at which Windows Phone (and Windows) devices people are actually using.

Some trends from this month's report include:

Lumia 520/52x continues to dominate. Worldwide, the contract-free Lumia 520 is still the most-frequently-used Windows Phone handset on earth, with 33 percent usage share, up from 31 percent last month. Factor in its variants, like the Lumia 521, and usage jumps to almost 37 percent. In the United States, the 521 and 520 together account for fully 42.3 percent of all Windows Phone usage.

Low-end Windows Phone 8 handsets dominate. If you look at all of the low-end handsets—the 52x and 62x series Lumias—you'll see that they represent almost exactly 50 percent of all Windows Phone usage, and probably more since that "other" category must have a few more in there too (like the 525).

High-end Windows Phone 8 handsets continue to lag. There's no good news to report on the high-end this month. The Lumia 1020 and 1520 don't make the worldwide chart at all. And if you look only at the US, the 1020 comes in a distant 8th with just 2.8 percent of all usage. I'm curious when/whether the just-released Lumia Icon (nee 929) will hit the charts.

Nokia hits 92.6 percent of usage. Basically, it's Nokia and then there's no one else.

And that's about it. No new devices to report, no major changes.