The Blackberry is proving more popular than the Apple 3G iPhone according to new research from the NPD Group which revealed that in the US market last month RIM’s BlackBerry Curve moved past Apple’s iPhone to become the best-selling consumer smartphone.

Helping them achieve sales was a two for one offer which resulted in RIM’s consumer smartphone market share increased 15 percent to nearly 50 percent of the smartphone market in Q1 2009 versus the prior quarter, as Apple’s and Palm’s share both declined 10 percent each.

Also performing well was the new HTC Google Android phone.

According to NPD “Smartphone Market Update” the top-four best-selling smartphones is as follows:

RIM BlackBerry Curve
Apple iPhone 3G
RIM BlackBerry Storm
RIM BlackBerry Pearl
HTC G1 Google Android 

The aggressive marketing of the BlackBerry Storm and its buy-one-get-one BlackBerry promotion to its large customer base contributed to RIM capturing three of the top five positions,” said Ross Rubin, director of industry analysis at The NPD Group. “The more familiar, and less expensive, Curve benefited from these giveaways and was able to leapfrog the iPhone.

Smartphones, which represented just 17 percent of handset sales volume in Q1 2008, now make up 23 percent of sales. “Even in this challenging economy, consumers are migrating toward Web-capable handsets and their supporting data plans to access more information and entertainment on the go.” Rubin said.