Since April, when AT&T started limiting its $19.95 per month Internet access pricing to 150 hours per month (formerly unlimited), ISPs around the country have been upwardly adjusting their pricing. Some regional ISPs have raised their rates for prepaid unlimited use by as much as 50 percent. Several other major regional and national ISPs have set limits on use. In the past three months, rates for corporate and institutional users have also begun to rise. The consensus in the industry is that the trend will continue because the majority of the nation's 4,500 ISPs are not realizing acceptable returns on investment.