Private property and all that. As long as it is posted nice and legal like I will do as they wish and spend my money elsewhere. Frankly, Costco is a bit too yuppified for my tastes. Sam's does just as well without all the froth. Sam's changes it policy and I go somewhere else. However, either or both company's will know exactly why I choose to reward another company.
"Given a choice between good intentions and human nature, I'll go with human nature every time."--Me, 2002.