There are 5 main reasons homes do not sell.
#1 The Price: you must be priced within your local market value. You have to be in-line with what other comparable homes recently sold for in your area. You must be in-line with other reasonably priced homes that are your competition. (of course the lower priced homes are going to sell first). If you are over priced then you will not be able to sell your home even if someone wants to overpay for the home. The reason being is that it must appraise for at least the purchase price for the lender to be able to loan the funds. Unless of course someone is willing to over pay with cash.
#2 Marketing Efforts: List with a professional Realtor, Local M.L.S. and Internet exposure are key. etc..
#3 Property condition/staging: De-cludder, Clean, fix unsightly problems, etc...
#4 Availability: Make your home available for showings, don't have ridiculous showing times. etc...
#5 Location: If your home backs to a freeway, don't try and sell it for the same price as the homes in the middle of the neighborhood. Or if it's on a busy street, awkward lot, next to junk yard, the part of town with the less popular school district, or whatever.