BOSTON (CBS) – Once a novelty, online learning is becoming mainstream on college campuses across the country. Some even predict it could become part of the solution to the skyrocketing costs of higher education. But many experts worry that replacing the traditional campus experience would deprive students of important life skills.

A student at Michigan State, Annabelle Loudon, registered for one class that is entirely online. “We’d have a reading assignment and then every week, you’d have a quiz or a test, so you could work on your own time during that week,” she said.

35% of all college students across the country now take at least one course online and 65% of colleges consider online learning as a critical part of their future. “In the last three to five years, the number of schools that are offering online degrees has exploded,” explained Vicky Phillips, founder of GetEducated.com.

Online classes offer flexibility, more choices of classes and teachers, and most importantly, affordability. “There’s a crisis right now in being able to afford even a first primary college degree. Online learning is a tremendous help to consumers in that regard,” Phillips said.

But some educators are concerned that virtual learning falls short of the traditional learning experience. “Campus life is very important in terms of leadership skills,” explained Kevin Kruger, president of student affairs administrators in higher education.

He believes a little bit of both may be the best approach. “The faculty member has some portion of the class that will be live, but they also offer many components of the class in an online environment,” he said.

Annabelle liked her online classes, but wouldn’t want her entire experience to be virtual. “I like showing up to class. I like being around other students and having people talk to me about the class,” she said.

Cost will clearly be a factor as online learning continues to grow. Some experts predict large lecture halls with hundreds of students could be replaced by online versions taught by faculty from institutions around the world.