Well I know several people, including me, who make a habit of keeping a list of items they want, and the searching the auction sites and amazon and etc., once a week, checking all those items. A three day auction has only a 3/7 chance - not even 50-50 of being seen by me, just blind luck depending the day of the week people are checking (I check early every Saturday morning, but who knows when other people choose too?). A 5 day posting will be seen by 5/7 of folks, better, but . . .
The more who see it, the more who might bid on it.