When I read a post that I find interesting, I give a 'thumbs up'.
But when I read a post that knocks my socks off, or opens my eyes to new information, or makes me roll on the floor with laughter, I send that person some acorns. It's sort of like giving a tip to an excellent server at a restaurant.
Sometimes you get acorns when you least expect it; like if you add a photo to the database.
Some people are 'rich with acorns' and give them away as not-a-raffle prizes.
