It does at least alter the expectations. A jar encourages you to toss your change in, and every little bit can be appreciated. Seeing 15%, 18% and 20% as the av

It does at least alter the expectations. A jar encourages you to toss your change in, and every little bit can be appreciated. Seeing 15%, 18% and 20% as the available options on an already overpriced coffee can make you even feel like more of a scrooge if you hold up the line manually entering 23 cents.