I don't eat at McD's, but you general see that cafes have a tip jar at the register (not Starbucks, but your local coffee shop, that is), while chains of all sorts don't. Oddly this isn't because they pay their staff a fortune... (though as was pointed out earlier, perversely many states have laws which allow for paying below minimum wage for jobs with tips, so ultimately no one in food service can really win).