Nokia’s Stephen Elop had a chance to go Android three years ago and opted to bet on Windows Phone instead.

So why, just as he is set to rejoin Microsoft, is Elop launching a new family of Android devices?

“It was very much the case, when we made the decision around our primary smartphone strategy, that picking something that fundamentally differentiated was important,” Elop said of the decision to go with Windows Phone then. “You see many other Android vendors who are in a very tough spot now building very credible if not great products but just unable to break through because of how that ecosystem has evolved.”

Now, though, Nokia needs an additional way to reach first-time smartphone buyers and sees the Nokia X as a stepping stone to the Windows Phone-based Lumia line.

Nokia says the X line will give it a chance to offer smartphones below the cost of Windows Phone, even as Windows Phone drops in cost as well. A key part of Microsoft’s announcements on Sunday were moves designed to allow it to run on lower-end chips and without some other requirements, such as physical buttons, that added to the cost and complexity of devices.

Whether consumers gravitate to Nokia X rather than one of the many alternatives using Google’s services remains to be seen. Also unclear is whether those Nokia X owners are more loyal to Android and its app ecosystem or to the Nokia experience and Microsoft services when they go to buy a new smartphone.

“We have to earn the right for that next purchase,” said Elop, who served as Nokia CEO for the past few years and is now the interim head of its device unit until the Microsoft deal closes. “What we’ve done, of course, is make sure the primary user interface is uniquely Nokia.”

Elop insists that Microsoft is on board with the Android strategy, for many of the same reasons we noted in a piece last year.

“There’s a lot of people in Redmond very excited about being able to reach, literally, tens of millions of people who have no other way of having an experience with Microsoft,” Elop said. “The average person that will buy a Nokia X does not have a PC, does not have a tablet, has missed that generation of experiences.”

That gives Microsoft an opportunity to profit from services in places where Office and Windows are not big sellers.

“In many of growth economies where the Nokia X will generate profit, there has not been an easy way for Microsoft to generate profit,” he said. “People aren’t buying PCs or software is not readily paid for.”

You can hear more from Elop on his big Android move in the video interview with Re/code, embedded above. (Also, as noted, he is no longer Nokia CEO, amid the pending sale to Microsoft.)