Article deals with paying for purchases by cash /debit cards/ credit cards and the discounts retailers can pass on to the consumer. I could see the benefit in doing this, instead of racking up airline miles points, cash back, you just take your discount at the register, stick it in a savings account and accrue the cash that way.

Since cash is out of the question, would online vendors give discounts for people who use their debit cards vs credit cards to pay for purchases ? This is where Credit Cards when hands down with fraud protection, extended warranties, etc..

http://www.usatoday.com/money/perfi/columnist/block/2010-10-12-yourmoney12_ST_N.htm