For-profit private charters are extremely risky.

By their very nature, private charters exist to make money for their investors. With limited funds incoming, there are only a few ways to limit costs so that investors can profit: skimp of supplies, suppress salaries, increase class size, limit employee benefits. Charter schools that struggle financially tend to go out of business during the school year, stranding students or forcing them back to a public school that wasn't prepared to have them.

For-Profit Private charters, generally, are not held to specific minimum standards for staffing, student acceptance (special needs kids? Race?), or academic standards.

They tend to be corruption magnets as public money crosses that line into an unregulated realm. Many have been busted all across the country in the past few years. Florida, currently, has seen a rash of fraudulent charter schools over the past couple of school years.

Public non-profit charters can be and generally are very effective as long as they are held to the same stringent guidelines to which public schools must adhere. Public charters in Virginia are excellent.