Greg Sullivan, Microsoft's Windows Phone marketing lead, was grinning from ear to ear when we sat down for an interview earlier this week. Market research firm IDC had just anointed his phone platform a solid Number 3, beating the once-dominant Blackberry platform for the first time.

"It’s very refreshing," Sullivan told me.

Granted, Windows Phone and Blackberry are fighting over scraps. That same report indicated that 92% of all shipping smartphones are on the Android and iOS platforms. Still, for Microsoft it's a victory of sorts — maybe even a sign of momentum.

Slow But Steady Wins?

Sullivan said Microsoft thinks of this progress in the way one would a flywheel. "It takes a lot of energy to start it and get it going and you see the progress and it feels like it's very slow progress. It's the tipping point; you get to critical mass or momentum that's self-sustaining."

The analogy is true of platforms as well, Sullivan told me. Microsoft knows, he said, that it's still shy of that "critical mass," and that things are "panning out, maybe a little bit slower than we hoped." But the company's convinced it's making the necessary progress. "Today's IDC report is evidence," he added.

While this argument makes sense when you look at Android — which took a solid year to achieve the trajectory that eventually made it the most widely-used mobile OS in the world — it doesn’t really hold up when you look at Apple and iOS, which seemed to enjoy remarkable success almost from the day the first iPhone launched.

Even so, there are signs that a new Windows Phone marketing strategy is emerging and, as with so many things, timing may be everything.

Window of Opportunity

It is fairly clear now that Apple will not be delivering an iPhone update this summer, which means Microsoft may have a three-to-four-month window to snap up just a bit more market share from those who are not interested in an Android phone. It's also likely that Microsoft will continue to gobble up more Blackberry refugees.

Is Microsoft taking advantage of that opportunity and getting more aggressive? Sullivan says the evidence is already there, starting with the cheeky Windows Phone "Wedding Ad." If you haven't seen this commercial (embedded below), it depicts a wedding where guest are using iPhones, Samsung Galaxy phones and other devices to capture the magic moments. Soon, however, the guests are arguing and then beating the heck out of each other.

It's a head-on approach we're more accustomed to seeing from Samsung, which has been attacking Apple fans for years.

As Sullivan puts it, the time is right for Microsoft to "put the pedal down."

Not only is Microsoft getting more aggressive in its marketing, but Sullivan noted, its partners continue to add carriers and devices (Microsoft also updated the mobile OS in January). Nokia, Microsoft's chief Windows Phone partner, recently rolled out the Lumia 925 flagship phone and the 920 follow-up, the Lumia 928.

Microsoft and its partners are also now covering the full spectrum of the pricing market, introducing handsets like the $129 Nokia Lumia 521 (a hit that apparently sold out in Walmart and on the Home Shopping Network). It's pictured above.

Filling that space is part of a broader Windows Phone strategy, and Sullivan said, recognition of three key factors that could help his nascent mobile platform grow.

First of all, there are still hundreds of millions of U.S. consumers who have not made the switch to a smartphone. There is also a new and growing trend to buy prepaid and off-contract devices. Sullivan contends that 1/3 of phones sold in the U.S. this past quarter were prepaid. It's also rare for anyone to offer a sub-$150 unsubsidized phone (like the Lumia 521).

The Magic Handset

Obviously, a $129 phone — even a 4G handset like the Lumia 521 — comes with some compromises (no flash or front-facing camera, a so-so-screen, plastic back and less processing power). On the other hand, it clearly fills that entry-level niche and may even grow Windows Phone market share. However, doesn't Microsoft need that one magical mobile product that sets the world on fire? For Apple, it was the first and virtually every subsequent iPhone. For Motorola it was the Droid and for Samsung, it’s been the Samsung Galaxy S3 (and, it appears, its follow-up, the Galaxy S4).

While Sullivan pointed to the Nokia Lumia 920, 928 and 925, none have sparked the same kind of buying frenzy.

"Yes, you need the device for you [and] me who lust after a device like this," said Sullivan as he held up the Lumia 925, "but not just that, because the volume comes from here," he added, holding up an older Android 2.3 device.

Progress Where It Matters

There are currently at least 100,000 Windows Phone apps, including many that really matter, such as Twitter, Facebook, Hulu Plus and Pandora. They even have the massively popular Temple Run game (but not my favorite actioner, Infinity Blade). Instagram, though, remains absent.

When I asked Instagram about future Windows Phone plans, a spokesperson told me, "At the moment, we are focused on building the best Instagram experience possible for people using iOS and Android devices. Our ultimate goal is to bring Instagram to everyone who wants to use it. We have nothing new to announce at this time."

Not a "no," but definitely not a "yes," either. Sullivan merely smiled when I asked him why Microsoft couldn't encourage its friend Facebook (Microsoft has invested hundreds of millions of dollars in the company and they recently worked together on integrating Facebook social results into Bing) to push Instagram on a Microsoft Phone build.

A bigger coup might be getting Vine on Windows Phone before Android.

Differences

Where Microsoft really differs, though, is in its approach to that entry-level smartphone market. Windows Phone, said Sullivan, looks and works the same on every phone — an Apple trait — but still offers a range of handsets, hardware features and, of course, pricing — an Android trait. In other words, it's a unique combination in the smartphone industry.

For someone who covers the mobile industry, this is obvious, but I don't think it's always clear to consumers. How, I asked Sullivan, does Microsoft better illustrate these differences?

"It's difficult in a 30- or 60-second spot to convey that," he said.

So Microsoft is going the "Geico" marketing route and delivering a variety of messages at once, hoping the "fundamental truths," as Sullivan put it, eventually hit home.

But how long will that take? When does Windows Phone finally achieve that momentum and take off?

"We can't put a timeframe on it," said Sullivan.

In the meantime, though, no question I asked could wipe the smile off Sullivan's face.

"It's becoming very clear who the number three guy is, as there's more and more evidence, the mounting evidence, for our solidified position as the third ecosystem. Of course, we're not going to stop there: Go for Number 2, Go for Number 1, that's what's going to help that flywheel spin."

What do you think of Windows Phone's chances to win in the smartphone market? Let us know in the comments below.

Image by Mashable, Lance Ulanoff