Yes there's a fee, but yet most retailers accept credit cards. That's because they know that people tend to spend more with cards, or gravitate toward merchants that accept cards because many customers think they're beneficial. Plus cash is costly to handle -- it takes a lot of manual labor and comes with the risk of loss, insider theft, and robbery if bad guys know you're a cash business.

Credit card surcharges used to be rare in the U.S. (and prohibited by merchant agreements) except at mom-and-pop small businesses. I am glad the OP called out the hotel. The 3% charge was possibly even more than the actual credit card processing fee, so just another junk revenue enhancer. It's as if they want all the benefits of accepting cards but then to pass off the costs to the customer.