WEST HAVEN -- Truth be told, a bad economy is good news for CampusBookRentals.com."We cater to people who need education and want to spend less money," says Alan Martin, company CEO and founder. "Renting textbooks was perfectly aligned with people in a recession going back to school."When Martin launched his business in 2007, the economy was good. But a year later, it turned bad. Martin calls the scenario serendipitous for his business, which now employs more than 130 local workers. "We've grown 8,000 percent as a company in four years," he says.