The airlines offer enticing intro offers like 50,000 miles, free checked bag, priority boarding, companion ticket, etc. However, the miles don't accumulate as quickly as others. There are sights out there that list the opportunities. I have a card with 2 miles/$ spent on anything, no blackout dates, convert to cash, travel or stuff. It really pays to pay for most of your day to day expenses on the high earning card.
