The Baltimore Sun is the latest U.S. newspaper to jump on the paywall band wagon and begin charging for access to its online content. But it's not just "professional" newspapers like the Baltimore Sun, New York Times, the Dallas Morning News and Boston Globe that have implemented paywalls -- paywalls now are spreading to college campus newspapers, too, according to PaidContent.

On Tuesday, Oct. 11, the digital subscription company Press+ and the John S. and James L. Knight Foundation launched a partnership that will allow the first 50 college newspapers that sign up with Press+ to install for free paywalls on their websites. The paywalls will allow the college newspapers to collect donations and subscription fees.

“The student journalists running college newspapers who hope to have a career in journalism are very aware that the traditional model is broken — advertising is simply not going to pay as much of the expense of newsrooms as it once did, especially for newspapers and magazines,” Press+ co-founder Gordon Crovitz said in a statement. “This generation needs to find new revenue streams, including new ways to collect revenues from the readers who get the most value from access.”

Besides teaching student journalists about the revenue realities of the newspaper industry, the "idea is not to charge college students for access to their own schools’ newspapers, but to get people accessing the websites from outside the college community to pay for access or just throw in a few bucks when they like an article," PaidContent explained.

Several college newspapers already have signed on, including Oklahoma State University’s Daily O’Collegian, Syracuse University’s Daily Orange, Boston University’s Daily Free Press, Tufts’ Tufts Daily, UMass-Amherst’s Daily Collegian, the Kansas State Collegian, and the University of Victoria’s Martlet. Oklahoma's Daily O'Collegian is thought to be the first college newspaper to erect a paywall, according to the Chronicle of Higher Education.

Previously, the Knight Foundation offered to give 10 non-profit news sites like ProPublica free access to Press+.

In an interview about the viability of newspaper paywalls, Bill Mitchell of the Poynter Institute said "charging today for something that was free yesterday is fundamentally a non-starter," adding that he didn't believe paywalls would ever replace all of newspapers' lost revenue from print editions. The future, he said, "will involve experimentation and at least as much failure as success. I think that changes will be as significant on the journalists' side as on the financial side because of the essential challenge of creating new value if you're going to seek new revenue. They're going to be creating new forms of journalism that are, for audiences and communities, much better than before."