We have several credit cards, all for different reasons, and all get paid off each month.
Citibank, mine...gives me 5% back for gas, groceries and drugs, and 1% off on everything else, up to $300 a year back.
Citibank, hubby's..same as above, but because we applied separately, we each get the $300 limit.
At & T, gives me 5% back on restaurants, including fast food, airfare, hotels
GM, gives me 5% back towards purchase of a GM vehicle..up to $700 a year.
Citibank Driver's edge, gives me 2 1/2% towards any car purchase, new or used, up to $500 a year.
We charge everything, and use different cards depending on the reward. Once we hit the reward on the citibanks, we fill up the gm and drivers edge. We use credit for everything. I seldom have more than $10 in my wallet. I make those cc's work for me, and never pay a penny of interest.
I have a savings, 2 checkings (one for my business) and an etrade account which is savings, stocks and checking.