Money is good and giving is good. Putting the two together is where problems come into play. Giving money is touchy subject that we often face in life due to deceitful people taking advantage of someone else' s generosity. You can say the same thing about Network Marketing sometimes. There are experienced predators looking for innocent prey, who want or needs an extra income source.
They make the product or service seem as if you can't live without it, take your hard earned money, and now your struck with an extra burden. So with that said, not all Pastors are crooks and not every opportunity is a "scam".
"A good man leaves an inheritance for his children's children..."