A school district in northern Indiana has sold the naming rights to more than $600,000 worth of athletic fields and classrooms and is looking to do even more.

Josh Boyd, an associate professor at Purdue University, says more public schools are looking at naming rights as a way to raise money.

It's an idea that started with professional sports teams and has taken root in cash-strapped public schools around the U.S.

A school district north of Chicago voted in March to postpone the introduction of a policy that would have allowed the sale of naming rights for those "who have contributed a substantial sum." Board member Debbie Hymen opposes this proposal, saying it doesn't put students first.