Microsoft (NASDAQ:MSFT) has very little experience playing challenger rather than champion.

For decades the company led the PC world with rivals including Apple (NASDAQ:AAPL) being the ones having to take extreme steps to get noticed. Now, however, in the smartphone world, Microsoft is the minor player struggling to get noticed by customers. And to do so, the company has borrowed a tactic from its longtime rival.

In 2006 Apple began its iconic "I'm a Mac" campaign where Justin Long personified the coolness of Apple's offerings while John Hodgman embodied the stuffy nerdiness of Windows PCs. One of the goals of those commercials was to make Macs seem hip while branding PCs as being for old people. The other goal of the campaign -- which ran for 66 commercials -- was to show how much more Apple's machines could do than their PC counterparts.

Microsoft is doing exactly the same thing in its new ads for Cortana, the voice assistant being offered with the latest update of its WIndows Phone software. The commercials don't star human dopplegangers for the voice assistants (though a befuddled Betty White as Siri and perhaps Natalie Portman as Cortana would have worked). Instead, they use the phones themselves to make it clear that Cortana is both useful and hip while Siri is less functional and decidedly uncool.

What do the ads say?
One of the commercials contrasting Cortana and Siri shows an off-screen voice asking Cortana, on a Nokia Lumia 635, to remind the user to wish his wife a happy anniversary. Cortana responds affirmatively, throwing in the wife's name, while Siri says "she" can't do that. To further show the differences in what the Microsoft assistant can do that Apple's can't, the Cortana user asks to be reminded to buy roses when he is near any flower shop. Siri is shown to not be able to do that, either.

So, in addition to learning that the owner of the Windows Phone is not very original when it comes to anniversary gifts, it's clearly established that Cortana is not only helpful, but a bit sassy, while Siri is mostly useless.

The ad ends with Cortana sending a traffic alert so the man does not miss his dinner reservations and Siri saying, "now that is a smart phone."

This theme is repeated in the latest commercial in the series which stars the Windows Phone 8 version of HTC's new flagship One Phone and Apple's current top model the iPhone 5S. Watch the commercial below.

Is Cortana better?
An iPhone user myself, I have mostly given up on using Siri. I was excited when Apple launched the voice assistant -- excited enough to order an iPhone 4S as soon as it was announced -- but my excitement turned to frustration when Siri was unable to respond to basic requests such as "where can I get a cup of tea" when I was in fact standing in front of a place which sold the beverage.

I pretty much abandoned Siri for good on the fourth or fifth attempt to call "mom" when it instead dialed "Bob," a casual business acquaintance who likely wonders why I call and hang up on him so often.

I've only had a limited opportunity to test Cortana -- a few minutes playing with one in the Seattle area, not far from Microsoft's Redmond headquarters. In that brief time, I found Cortana more able to answer requests such as "where can I get a cup of coffee" than Siri and after quickly adding a number and labeling it both "mom" and "Bob" it was successfully able to repeatedly understand me when I asked to call "mom."

Though my opinion is anecdotal and I'm sure a longer test would find failings with Cortana, Preston Gralla at Computer World did a much more extensive test and agreed with the claims in the Microsoft ads:

In tests I've run so far on the HTC One M8 for Windows and on the iPhone, I'd have to say that for as far as I've gotten, Microsoft is right. Cortana is more useful than Siri. It provides more detailed, useful answers and help in whatever I asked it to do.

One review does not decide things, but everything I experienced, and everything Gralla writes, is backed up by Matthew Miller at ZDNet. "Cortana truly is the personal assistant that I have wanted for a few years and that make our smartphones finally as smart as they should be," he wrote.

Siri had promise but it has mostly failed to deliver. Cortana appears to actually work, but Microsoft faces an uphill battle making anyone care.

Can Microsoft make it work?
Siri, though it was met with much excitement at launch, has proven mostly a novelty that's marginally useful at best. This may have poisoned the well for all future voice assistants -- at least for a time -- as the public believed the hype once before and was left disappointed.

Microsoft has been growing its share of the mobile phone market, reaching 3.6% in July, according to comScore, up from 3.3% in the previous quarter. That's still a tiny fraction of Apple's 42.4% market share, but it shows that growth is possible.

Cortana may be responsible for some of that as the ads did air during some of the period covered. Cortana may be the killer feature which makes people consider Windows Phone if Microsoft can convince them that Cortana delivers on what consumers once expected Siri to do.

If the PC maker can show users that a voice assistant can be not just a gimmick, but an essential and useful feature, then the ads touting Cortana may help make Microsoft a smartphone player. 

Daniel Kline is long Microsoft and Apple. He would consider a Windows Phone is Sprint, his carrier, offered a decent one. The Motley Fool recommends Apple. The Motley Fool owns shares of Apple and Microsoft. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.