This is highly dependant on several things. Price, how it's staged, what was updated, location, etc. If you have a home which is priced right, staged well and pretty much all ready to move into, it will sell quickly.
You have to make your home the most appealing one amongst all the other similar homes in the area. If it isn't, it will stay on the market for a long time.
Hope that helps,
Terrence Charest, e-Pro