Here's the deal: I react poorly to request for money for charity from people I know have more money than I do.
For example, we have all of these NFL players shilling for the United Way. What percentage of their time and money do they give?
The proximate occurrence in this case is Staples asking customers if they'd be willing to make a 2$ donation to school supplies for kids. No problem with the cause. But notice the stronger language: not 'would you like to', but 'would you be willing to'.
The two customers in front of me were asked, but I was not (probably because I was using a corporate credit card).
Situation in which I might be 'willing': give me some time to think about it and match my contribution. Then I know you're giving, too.
What do you think? Am I just being petty?