I know there are rewards systems and suck out there. But what if we wanted to give our customers say $2 a month if they made over 15 debit card purchases? Does anything prohibit this?

You are free to give away your bank's shareholder's money in any properly disclosed manner you choose, as long as it doesn't involve a lottery.

we have a local bank that advertises if you use your debit card as credit mode, they pay you $.10 per transaction, no limit.

Why? The bank isn't making that much in interchange, surely! I really don't get why you'd want to pay your customers that much!

obviously they feel they are making enough on the interchange to make it cost effective to have their customers use this method and increase their revenue.

I would love to see before/after metrics from that bank's campaign. there is no way $0.10/transaction would alter my behavior. Curious if it is really altering anyone else's.

my wife uses our debit card, on average, about 150 times a month...i use it about another 30...that would be an extra $360 for us annualized...not a bad return for no additional work on our end...

Happy, what kind of math are you doing? I see two examples listed above - a flat $2.00 per month, or .10 per transaction - which would net you and your wife $18.00.

180 transactions per month, at $.10 per transaction, for twelve months in one year.

180 x .10 = 18 x 12 = 216

So neither one of us can do math!
(Yup, there's a reason they don't let me handle the money around here...)

sorry, it is $216, fat fingered my calculation...

I figure it this way: 180 transactions per month x average transaction amount of $7.50 = $1350/month x 12 months = $16,200/year = 16,200 American Airline miles through Citi A'Advantage card.

Round trip ticket from DFW to pretty much anywhere is 25,000 miles or roughly $400+tax. $400 / 25,000mi = $.016/mile

$.016 x 16,200 miles = $259.20. $43 extra dollars plus plus free bags ($25/leg), priority boarding ($20/leg), in-flight booze discounts (immeasurable), and a few other perks.