I've seen this question posted before; however, it seems like everyone has a different answer. So I thought this might be a good topic to set out there in order to get some truth in all the different speculation. If a person has great credit, never carries balances or incurs finance charges of any kind, what, if any, are the effects of applying to many mileage credit cards and then canceling them once bonus miles are awarded?

I've seen many articles written by creditors on the subject and they all seem very vague. They all suggest that it may effect credit. Has anyone had any real experiences with this or has had their credit score hurt by applying to and canceling too many credit cards?