It's my experience and may be that of others too that buyers bid and then don't pay in spite of reminders or just come back and say after a few days to say that they bid by "mistake". All this while the artwork loses a chance of selling to others as it will be marked as "sold" which I think is unfair on the artists . As long as the supply is in excess of demand as in the case of artworks this probably will continue to happen.
But I propose is that the winning bidder need not be given 4 days time to get flagged.They may not be checking their emails like the desperate artists but in these days of smartphones it's so easy to get to one's emails without the need to go to one's PC. Therefore my suggestion is that they be given only 24 hours time to pay ( 24 hours from the close of the auction). If not paid, DPW can program for auto cancel of the bid and release the artwork for sale again.
If this condition is made, the buyers will also expedite and remember to pay immediately, if they so much want that piece of art. If they miss out, let them bid again, if they are really serious about the art. Giving 4 days of time, then flag for friendly reminder etc is amounting to demeaning artists and their artworks. Buyers may be few, but they need not be encouraged to treat artists very casually is my strong feeling. I hope David will understand what I am trying to tell, give us artists the much needed dignity. I wonder if my fellow artists feel so too?