4. If a transaction is submitted within 7 blocks but does not become part of the main chain within 1000 blocks the purchase order is canceled. If the transaction becomes part of the main chain after the purchase order cancellation then nastyfans will refund the amount (minus 0.0005 BTC tx fee) to the buyer if the buyer accepts donations. Otherwise it becomes a nastyfans donation. (This is new policy.)
Why the need for the donation distinction? Why not just send back to the sending address? I think taking funds like that could make nasty fans look very bad in the future.
You can not assume that people have access to receive Bitcoin from the sender address.
Most people use online services and the sender address belongs to the service not the user.I would love to send it back. But Bitcoin does not work like that. If there is no donation address then there is no guarantee that the Bitcoin is sent to sender.
I would say that is a pretty bold statement. Also not all online services work that way, BlockChain.info's MyWallet for example works exactly like a desktop wallet, while InstaWallet functions as you say.
I would still say it is a better policy than just taking the coins and saying 'oh well... thanks for the donation'. Several sites/services that REQUIRE the user to be in control of the sending address exist and have been very clear and don't seem to have an image problem.
I guess we could have a new option in settings:
[ ] If my TX has a bunch of dust inputs, so it is unlikley to get confirmed in a timley manner, then just treat seat purchases as a donation. (If this option is unchecked and TXs are not 6xConfirmed in 144 blocks after your TX then it will be sent back once the TX eventually confirms (miuns 0.0005 fee).
But I don't really like that option either. I think a simple warning on a purchase is much more sane:
WARNING: If your TX is not 6xConfirmed by block # xxxxxx (approx XYZ hours from now), then once it does finally confirm it will be sent back to you minus 0.0005 TX fee. This is to ensure that seats are not locked forever.
One reason I am so adamant about this is because it is very possible for this to happen completely out of the users hands with many small inputs. If their client doesn't do the right thing, or even if it does some mining pools will deliberately prioritize large TXs with small amounts. Also a message about using the correct fees might be good.
/rant off