Two days ago, the company formerly known as RIM pulled out all the stops at a super-swanky event in New York to launch two new phones that will either kill or cure the company.

Despite the global launch happening in the U.S., America will be the last in the first batch of countries to see the Z10, BlackBerry's first phone to ship with its new OS, BlackBerry 10. Americans have to wait until March to buy the touch-screen phone, but it became available to buy in the U.K. yesterday. That's six days ahead even of BlackBerry's home market in Canada. On the face of it, this seems like a strange decision: why release the Z10 in a relatively small country first?

The overriding reason, according to Francisco Jeronimo, research manager for European Mobile Devices at IDC, is that the U.K. is the biggest BlackBerry market in the world. Contrast his figures: in the third quarter of 2012, BlackBerry had a 12 percent market share in the U.K., with Apple at 25 percent. In the U.S., BlackBerry accounted for just 2 percent to Apple's 25 percent.

Speaking to CNET at the U.K. launch, BlackBerry senior VP Andrew Bocking echoed this point: "The U.K. has been a key market for us for so long. We have over 8 million BlackBerry users today in the U.K. and we are very excited for them to be on the leading edge getting access to BB10 on the Z10."

Some of the biggest buyers of BlackBerry phones in Britain are teens, partly because the phones are very cheap, partly because of the appeal of BBM, the free instant messenger program. So popular has BBM become in Britain that the 2011 riots in London were blamed on the service by some politicians and members of the police, although its role was likely exaggerated.

Jeronimo argues that it's not just about teens gravitating toward BlackBerry phones: "Most companies have their corporate e-mails running on BlackBerry servers. To change the entire mobile infrastructure is not cheap or something that can be done overnight....When we ask if companies want to move to another platform, it is very clear that the majority don't."

Leaving the size of the U.K. market aside, market watchers have a few other ideas about why Britain is first up with the Z10. Ian Fogg, analyst for IHS, made the point to me that a successful launch in the U.K. could have more global impact than a U.S. launch, as the owners of U.K. carriers are present in other countries, whereas the U.S. carriers are more self-contained.

Several analysts made the point to me that they have been impressed with the speed BlackBerry has shipped its phones. Jeronimo says: "I don't remember the last time a major vendor launched a flagship device and made it available in stores the day after. BlackBerry probably didn't get the same support in the USA and therefore decided to launch it later."

Now that the Z10 is shipping, what's BlackBerry's game plan from here? Over to Ben Wood, chief of research at CCS Insight:

"Its first concern will be the long-time older BlackBerry owners who initially had a BlackBerry for business and have continued to tough it out in recent years. It must also convince former BlackBerry users, [although] many of these guys will be locked into a contract so it could be some time before they can even consider going back to BlackBerry."

"The final group it needs to nail are the teen-agers and 20-somethings who are still hooked on a BlackBerry because of BBM and Facebook. This group is unlikely to be able to afford the Z10 or Q10, so the next milestone in the U.K. market will be getting some cheaper products available."