BlackBerry unseats iPhone as most popular smartphone in Q1

During the three-month period ended March, RIM's consumer smartphone market share increased 15 percent to nearly 50 percent of the smartphone market versus the prior quarter, according to market research firm NPD.

The rise was good enough unseat previous top-slot holder Apple, whose iPhone along with handsets manufactured by Palm saw their share of the market each decline by about 10 percent.

NPD attributed the shift largely to an aggressive "buy-one-get-one" promotion by Verizon Wireless that helped RIM's BlackBerry Curve move past the iPhone to become the best-selling consumer smartphone in the U.S. in the first quarter.

"The more familiar, and less expensive, Curve benefited from these giveaways and was able to leapfrog the iPhone, due to its broader availability on the four major U.S. national carriers," said analyst Ross Rubin.

The promotion also contributed to RIM capturing two additional top five positions, namely the the third slot, which went to the BlackBerry Storm, and the fourth, which was made up of all BlackBerry Pearl handsets with the exception of flip models. T-Mobile's G1 handset running Google's open Android software was the fifth most popular smartphone during the quarter.

Overall, smartphones saw their share of the global cell phone market rise 6 percent on a year-over-year basis to 23 percent. Rubin sees this as a sign that, even in the challenging economy, consumers are "migrating toward Web-capable handsets and their supporting data plans to access more information and entertainment on the go."

Apple's fall from top of the smartphone charts wasn't unforeseen. The Cupertino-based company said last month it shipped 3.79 million iPhones during the first calendar quarter of the year. By comparison, RIM sold a record 7.8 million BlackBerries — or more than double the number of iPhones. — between December and the end of February.