Public schools exist for one reason and one reason only. People can argue about the best ways to teach, the right subjects in the curriculum or the menu of extracurricular offerings, but in the end, the point of a school is to educate students.

Corporations also exist for one reason, but it’s not the same one: They exist to create value for shareholders.

They don’t mind if their customers are happy – they don’t tend to last long if the customers aren’t – but customer satisfaction is not essential. It’s the shareholders that matter, and without profits, the corporations are out of business.

This makes public schools and for-profit corporations a bad fit. And that fit is what the Maine Charter School Commission should consider as it reviews the applications of two for-profit corporations that want to use public money to run virtual schools. The commission has turned down both corporations’ applications twice, and it should do so again. There is not enough money in Maine’s public school system to pump up stock prices on Wall Street.

The two proposals, from Maine Virtual Academy and Maine Connections Academy, both claim to be local organizations. They both have local boards that include prominent local people. But they both also have exclusive contracts with for-profit vendors that will supply the staff and materials to deliver online education.

This is a model similar to the one used by fast-food chains: The franchise may have a local owner, but the hamburger in Augusta, Maine, came from the same place as the one in Augusta, Ga., and there is nothing the local cooks can do that will make them taste any different.

Maine Virtual Academy contracts with K-12 Inc. of Herndon, Va. Maine Connections Academy would work exclusively with Connections Learning of Baltimore.

If approved by the charter commission, the virtual schools may benefit some Maine students. But one thing is certain: Taxpayers would be sending money out of state to support these companies, paying staff salaries and creating value for their stockholders.

There may be a place for virtual schools in Maine. Thousands of families choose to home-school and could benefit from the option of online education. It could be an affordable option for students isolated by geography, or a temporary solution for children who can’t get to school because of illness or a disablity.

But why should private, for-profit companies be the beneficiary? Maine could do better by creating its own virtual school option, working with a variety of vendors in a competitive market.

The charter commission should turn down K-12 and Connections Learning one more time, and let others work on a truly public virtual school, that puts students first, not stockholders.