BlackBerry is now considered as one of the most used smart phone in the world from the customers perspective. So blackberry was first established in Canada, then started to move globally to generate more profit in for the company, and also to generate a strong global brand name.
Blackberry entered the UAE (United Arab Emirates), because it saw a big opportunity in this market. BlackBerry is known for its easy use and internet connection for businessmen, and it became one the most famous communication phone by using BBM ( BlackBerry Messenger). And UAE became one of the biggest business countries in the world, and population became more and they saw the tendency for people to communicate to gather. So personally I believe that BlackBerry wanted to increase their profit and grow there goals to make their brand name more global.
BlackBerry is now ranked as number 54 top world brands in the 2010 report (http://www.interbrand.com/en/best-global-brands/best-global-brands-2008/best-global-brands-2010.aspx).