I don't think tarring the whole enterprise with the teleevangelism brush is particularly fair or sensible. Think more of your typical church. It provides a number of services, paid for by donations - I don't see that as an abuse of non-profit activities. What the church does or doesn't give to charity is largely irrelevant; the core activity is non-profit.
If this is true then they would have 0 issue not being tax exempt. The taxes they pay would be very minimal as most of their activities would be write offs. However, many churches spend allot of money on questionable activities, but simply because they are a church they are not required to be held accountable for them. Every charitable organization is required to fill out a detailed account of their expenses to make clear what is charitable and what is not. Churches are not. They can spend their money on a great many things that are not charitable and often do. This activity should be taxed and churches should be just as accountable as any other charitable organization.
And guys, I really wanted some facts over money lost. It would be nice to have for an argument. The closest thing I have gotten is a few unsourced claims on atheism.about.com