Microsoft today shared some details about the Windows Insider Program. Most notably, the company says it now has over 1.5 million registered users testing its Windows 10 preview (up from 1 million on October 13), with “about 450k” (approximately 30 percent) using the test builds every day.

Compared to previous Windows beta releases, including for Windows 7, Windows 8, and Windows 8.1, preview builds of Windows 10 are getting more usage. Microsoft has put its internal data into a handy graph for Windows geeks to salivate over:

“It’s terrific for us to see this, because that hardcore usage will help us fix all the rough edges and bugs,” said Gabriel Aul, the leader of Microsoft’s Operating Systems Group’s Data and Fundamentals Team. “The reports you send us, both from automated things like crash logs and manually via the Windows Feedback app, are helping us shape the product.”

Aul said his favorite recent example of a manual bug report is for a bug that he says would have been “really tricky to catch with test automation or by other means.” In certain circumstances, the OneDrive icon in File Explorer was replaced by the Outlook icon. That’s embarrassing, confusing, and hilarious all at the same time.

Microsoft said it has fixed almost 1,300 bugs that users have reported or upvoted so far. Keep in mind that some bugs naturally get many reports, so thousands of reports can sometimes spring from a single bug.

Here’s the per-build breakdown:

While many of these are “just bugs,” Aul also noted that some result in changes to the design or in completely new features. Examples included adding an option to choose which folder is the default when opening File Explorer, the ability to turn off recent files and/or frequent folders in Home, and a little animation/transition when opening the Start menu.

Microsoft has also fixed the most frequently occurring bluescreens and user mode crashes reported by testers in build 9841, build 9860, and build 9879:

The tall line in the chart on the left is the 0xAB bluescreen, and the tall line in the chart on the right is the Explorer.exe crash. Both were patched in build 9879.

Microsoft is expected to release the next build in about a month, in line with its Windows 10 consumer event on January 21 or soon after. The company is promising “a bunch of new features and improvements.”

Expectations are sky high. In fact, the build branch is called FBL_AWESOME.