[Grampa Dave]

The problem with bumper stickers is the limited space and the need for immediate mental impact with a few words.

I vaguely remember reading years ago that once you got past 3 words, each 4-5 letter word added to a bumper sticker reduced the impact by about 20%.

[AFPhys]

Yes: I realize that adding "Old Media" might reduce the impact, and considered adding such a note to my post.

Your "20%" is daunting, though... Perhaps leaving it out is best.