It's currently possible to complete a transaction on the Chia network without paying any fees. This is due to the low volume of transactions but is expected to change once transaction volume increases.
Once pools are online, we expect transaction volume to increase dramatically, as the pools start creating transactions to pay their members. As a result, the addition of transaction fees will become necessary in order to incentivize blockchain participants to process transactions.
As a result, pool members (members of Belly Flop Club as well as those of other pools) will need to consider transaction fees when receiving payments. Simply put, it makes more sense to send a larger payment less frequently if smaller payments are eaten up by fees.
To avoid losing a large percentage of any given transaction to these fees, we plan to implement a minimum payout threshold which must be reached before we initiate a payment to a pool member's XCH address.
We don't currently know what that minimum threshold will be, as it will depend on network congestion, but hope to strike this balance: keep the minimum low, but keep it large enough that it won't be in constant flux as network congestion varies from day to day. We believe this will keep things simple to explain and reduce the likelihood of confusion for our members.