<prompt> Human: I have to travel by plane a few times over the summer and am trying to do so as cost effectively as possible. Many airlines have deals such as spend 1,000 on this credit card in the first 3 months and earn the miles equivalent of a round trip flight. The only catch is that these credit cards tend to have yearly fees of around 100 after the first year.So my question is should I take advantage of these offers? I would be using the credit cards on things such as groceries and miscellaneous expenses and then promptly paying the balance, so I wouldnt be creating a credit card debt just for the travel miles reward.My other question involves canceling the card. The rewards really arent good after the initial bonus reward. Would canceling the cards after the first year hurt my credit in any significant way? I currently have 2-3 credit cards and dont carry a balance on any of them.Thanks for any advice.  <response>: Depends on when you want to apply for a big loan car or house. If you dont want to take on a big loan in the next year or two, go for it.Check out rchurning. 