"When you zap someone, you can opt to “send a reply with your zap.” This could be a simple message, an image, a video, a link to your website, etc. Zaps on a note are ranked with the highest zapped amount at the top, so the more you zap, the higher up in the zap list your comment will be."

I don't see any option to include a note with a zap on amethyst app on my Droid... This sounds like a great advertising model I would like to try.