Churches: Tax-Exempt For Doing What?

"Every year churches collect some $100 billion in donations. But most donors do not know that the average congregation in the U.S. gives only two percent of donated money to humanitarian projects. Some 98% goes to pay staff, upkeep of buildings, the priest’s car, robes, salary and housing."

One of several links I could post showing the truth about churches and charity. Also, if one defends the salaries, etc. of the clergy, please tell me why paying for staff to provide placebo is ethical, especially when they are not only tax-exempt but their books are secret? 

With very few exceptions, the financial statements of churches and religious ministries are not available to the public.