Make Yourself Useful, MBAs

Question for all the marketing MBAs out there: Why does every appeal letter (and we are getting tons of them this holiday season. Give! Give! Give more!) repeat the request in a P.S.? I mean, if you've made it that far, you've already got the point. Do they think that most of us will read the letter and lose our stream of thought halfway through, get to the P.S. at the bottom and then say, "Oh, yeah! They wanted money! I totally forgot. Let me go find my checkbook."