Research In Motion Limited (RIM) has sold its 50 millionth BlackBerry smartphone, with 3.9m BlackBerry subscribers signing up in the company's fourth quarter, which ended on February 28.

Analysts have predicted that the recession may actually help companies such as RIM, which reported record high revenue of $3.46bn in the quarter, due to its focus on smartphones.

People may cut back on buying expensive goods such as cars, and on new holidays, and instead buy smaller items or devices for the home, such as LCD TVs, netbooks and other electronics.

A holiday-season survey by market researcher IDC in December found that most people planned to focus purchases on family and home for the holiday season, with half of respondents saying they would buy electronic devices before the end of the year.