When I do a transaction with someone here,buying or selling I provide my email address & home phone number.Most guys when they see I provide that do the same.I do it because I am on the internet once or twice a day.That being said some folks have no sense of urgency to reply ever about a transaction.I always let the other person know when I send an MO or PP.I always provide a Tracking number when I ship.I want to hear from the person I sell to that they are satisfied with what they bought.All this is just common courtesy .Apparently some thing some folks were never taught.I think 4 days would be a fair amount of time to wait before you put up for sale just incase that life got in the way of the persons answering you.