Studies show that people who use plastic spend more than those who use cash?

[ExcuseMyIgnorance]

Social science is pretty clear on this point - cash back credit card rewards actually prompt their users to spend more more.

See = >

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=1719054

Abstract:
Using a unique administrative level dataset from a large and diverse U.S. financial institution, we test the impact of rewards on credit card spending and debt. Specifically, we study the impact of cash-back rewards on individuals before and during their enrollment in the program. We find that with an average cash-back reward of $25, spending and debt increases by $79 and $191 a month, respectively during the first quarter. Furthermore, we find that cardholders who do not use their card prior to the cash-back program increase their spending and debt more than cardholders with debt prior to the cash-back program. In addition, we find that 11 percent of cardholders that did not use their cards in the previous 3 months prior to the cash-back program spent at least $50 in the first month of the program. Finally, we find heterogeneous responses by demographic and credit constraint characteristics.

[LivingAlmostLarge]

I have to say I use a CC exclusively but i couldn't tell you anything I buy that I wouldn't have bought without cash. And I certainly don't buy anything for rewards. I don't even have the best rewards cards. I just have one because we use a credit card. But since we are going to try and buy this year I'm trying not to hammer my score by opening and closing cards.

So not everyone who uses rewards cards are charging or chasing rewards. Just getting rewarded for that which I would spend anyway.