Some people seem to think 3 or 4 is adequate for a routine transaction. Which it should be on a scale of 1 to 5.

eBay however have deemed anything under a 4.4 average (which equates to 40% think perfect and 60% very good) as unacceptable. Thus the sellers' expectations are geared to 5s, whereas the average buyer, especially if they're new or don't come to the boards, probably reckons they're doing the seller a favour by giving them 4.