A recession is usually bad for business, especially when it comes to cellphone carriers with their monthly charges, overage fees and rates for data plans. On the other hand, a poor economy is good news for at least one networker. MetroPCS reported this morning that the number of subscribers in the first quarter jumped 51% from the total at the end of last year's first three months. This was the third straight quarter of growth for the regional carrier and the 684,000 net new customer additions was a record for the firm and was a lofty 32% above the net additions posted in the prior quarter. The churn rate rose 1% to 5% in the period. Chief Executive Roger Linquist said the company was off to a "very strong start" thisyear. Offering a flat rate unlimited calling program, MetroPCS usually benefits from bad economic periods when high cellphone bills force consumers to start shopping for the lowest price rather than looking for extra services.