I've already done my own such "challenge" years ago, in response to so many claims that 'tithing' leads to financial blessings, and it failed. If people weren't so shallow about this I would not have been inclined to
test God that way. One lady I can't forget claimed that being a faithful tither resulted in her being absent from her job at the cotton mill only 4 days in 14 years.. maybe she really only gave 9.98%
. The conclusion has to be that OT tithing, as in the familiar Malachi passage, is not applicable to the NT individual, as so many claim that to be.
But I have to agree with the article cited, that this guy is manipulating (as many pastors and other 'leaders' do), and he is a lot like a "miracle" product sales spot on television-- many people may be dissatisfied, but few of those will actually go through the steps to get their money back, and there will be a net gain overall to the business or the institution. Having played that once-- though 'solitaire'-- I won't get into it again.