NEW YORK (TheStreet) -- Investors are looking forward to improving first-quarter earnings before the market opens on Friday. Analysts' expectations for Research In Motion's (BBRY) range from four cents per share to the most optimistic view of a profit of 50 cents per share.

Figuring out BlackBerry's quarterly earnings is no small feat. Unlike


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Android and


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based phones, you can't use what you see around you as a gauge.

Understanding Google and Apple's smartphone market share progress is relatively easy; you could see it all around you as people traded in their BlackBerries for another brand. While BlackBerry was turned into berry juice in North America, the rest of the world continued buying enough of the Canadian smartphone products to keep the company afloat.

Sales outside North America make up a significant amount of revenue. So much so, that if you make the mistake of using anecdotal data, you're likely to underestimate shipments. BlackBerry continues to have success in the emerging market space including India and Indonesia.

Not all shipments are created equally though. Emerging markets represent growth opportunity for all manufacturers including American, Chinese, Korean, and Taiwanese. It's impressive that BlackBerry found a way to give legs, albeit lower margin legs to its older smartphones, but that can only last so long if they are not producing new high-end phones.

Also see: There's No Question Now: Apple is Dead>>

Other mature handhelds from the previously mentioned countries will continue to exert greater pressure on older BlackBerry while Apple, Andriod, and


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based phones will limit BlackBerry's prospects on the upper end. Ultimately, investors should expect a self-reinforcing feedback loop sending BlackBerry into the dust bin unless they can follow up Z10 (soon) with another equal or even better product.

CEO Thorsten Heins has navigated BlackBerry from the drain as superb as anyone could ask, but smartphones are still a tech product, and consumer tech products have a way of becoming commodity items. The Z10 will begin to show its age by the end of summer, and if BlackBerry has any hope of a strong 2013 North America finish, "Z11" better be on the shelves.

The problem for shareholders according to short sellers is that the Z11 won't be on the shelves. Absent a strong product during the fourth quarter, North American market share and the spoils of victory may move further from BlackBerry's reach. That's why

short interest

continues to climb and is now at the highest level during the last 12 months.

Also see: The Energy Credit is Still Here For 2013>>

I want to believe BlackBerry has more fight in it, and Heins has another trick up his sleeve, but those who bet against short interest this high usually end up on the wrong side of the trade.

At the time of publication the author held no positions in any of the stocks mentioned.

This article is commentary by an independent contributor, separate from TheStreet's regular news coverage.

Robert Weinstein currently blogs, mentors traders, and writes several weekly columns in Rocco Pendola's Option Investing newsletter from his home in northern Wisconsin. Robert tends to focus on the psychological importance of goals, risk mitigation, emotion, and relatively short term market exposure. With nearly 30 years of studying and investing experience, Robert has experienced the many ups and downs in the financial markets and uses the knowledge gained to maintain balance. Robert believes the best way to make money investing is to avoid losing it. The best way to avoid losing is to know what emotional traps lay in the path of investors and learning how to avoid them. Robert is a voracious reader of financial related books often completing more than one book a week while not trading or writing. Robert contributes to his blog at on a regular basis with an emphasis on studying behavior finance.

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