Coins
From Digibutterwiki
Coins are the standard currency on digibutter.nerr.biz.
Earning Them
You get one coin per post, with the exception of the Off-Topic forum. Another way to earn coins is to beat the hi-score at the arcade. Other ways include: Selling things in your usershop, receiving donations, winning a game(mostly in the Star Carnival), and making things (such as avatars, sprites, animations, cards, and signatures) for people in the Black Market.
Losing Them
You lose coins for bumping and double-posting.