Great question!
Fishbucks were established some years back on the fishing side as a way to keep the classified ads and a few other miscellaneous tasks free here at iDo. As the site grew, the requests for the moderators time continued to increase. We also had folks trying to use the general forums to sell stuff and it was a bit crazy for a while.
You get $0.02 for each post. Should you ever want to post in the classifieds or need your avatar changed by an admin, your fish bucks will be used. In essence they have no monetary value. However, he with the most $bucks wins in the end.
P.S. It’s not uncommon to see newer members go negative at first as they upload an avatar etc…
Any other questions, let me know.