I have a buddy that actually looked into this sort of thing with a company that did the pay by ball thing. The OP left out so much information it isnt even funny. Like for instance that in order for them to pay per ball, they only take shipment by PALLET.. yeah , in order to get paid you have to ship them recovered golf balls by the pallet. Oh and you pay for shipping and then after they get the recovered balls and count them, THEN you get paid.
another poster had a better idea, find the balls, wash them and take them to the flea market for a $1 a ball, or turn around and sale them to the golf course for them to resale.
There is actually a company in my neck of the woods here in florida that has turned this sort of thing into a substantial business, but what they do is they do contracts with the local golf courses. They get paid to come in monthly to clear out the ponds and water hazards. The courses then pay them, not per ball but the agreed upon contract amount. Dont get me wrong, it isn't $100,000 a year, but at the same time, its providing for their family.
The OP might want to rethink their marketing scheme before they try this advertisement again