"We think it's the right approach. One of the things that gets people and the leading edge influencers that really know all the details about smartphone platforms excited about a platform is a steady and frequent cadence of new devices for that platform.
"We see that across the board. Apple is kind of unique there, I would argue, but certainly in the Android space, this kind of frequent delivery of new devices is one of the things that keeps the buzz and excitement around the platform. It's a benefit.
"Nokia has shown that its ability to offer a broad portfolio of devices with a lot of choice is a good thing for customers. And now, combined with our software and the consistency of the experience across that whole range, it's a really powerful selling point. There's a strong argument when we're trying to compete against these guys."
"These guys" in our conversation centered on Android specifically in the feature phone space, a market Microsoft wants to attack with devices like the Lumia 521, which sells for $129 (around UK£85, AU$133) at Wal-mart, $149.95 (around UK£99, AU$155.35) through HSN and now a $29.99 (around UK£19, AU$31.06) down payment at T-Mobile.
"One of the things that's a trend in the industry we're seeing is not just the high-end super phones that get a lot of attention," Sullivan said. "Roughly a third of smartphone purchases in the U.S. in the first quarter of this year were pre-paid. That's a significant increase from the previous year where it was about 21 percent. That dynamic has been true outside of the U.S. where the subsidized model is not as prevalent, but it's increasingly happening in the U.S."
Forty-eight percent of stateside phone owners have feature handsets, Sullivan said, a figure that has Microsoft licking its chops.
Smartphones shipments are expected to outstrip feature phones worldwide this year, according to predictions from display market research and consulting firm NPD DisplaySearch, but MS sees the non-smartphone sector as enough of a reason to pump out more non-high-end devices.
"Yes," Sullivan answered to a should-we-expect-other-cheap-phones question. "The way we think about it is we're not going to solely focus on that segment...but given that this is where a lot of the volume is, and this is a trend that's increasing in the U.S., which is of course a key market that leads from a perception stand point in mobile. Yeah, we'll have more."
Nokia - which Sullivan referred to as a "unique partner" due to its full commitment to the Windows Phone platform - lost out on the feature phone sales in the first quarter of 2013 thanks to cheap Android devices, according to figures from Forbes.
A dedicated push by Microsoft and the phone maker could turn the tables, however. According to a statement sent to TechRadar by Microsoft, Lumia 521 sales are similar to those of the Lumia 520 - "the fastest selling Windows Phone mid-tier device ever" - though we didn't receive any figures.
"There are so many sacrifices you have to make on an affordable Android phone relative to a $129 Windows Phone.
"Once we expand the reach of this kind of offering, it's so dramatically better. Frankly, I was pleased with how bad the experience on affordable Android phones [was], because ours is so great. If people are willing to settle for two-and-a-half-year old software that won't get updated, boy we have a real opportunity to show that they don't have to settle. We can raise people's expectations of what a $129 smartphone can do."