The property needs to look good from the street, up the sidewalk, on the front porch, through the house, in the darkest closets, and even in the attic. You definitely want to give the impression of a well cared for home. You want the prospective buyer to feel that this home is quality all the way through, not just on the surface. You'll never have more activity on the home than you will in the first three or four weeks of the listing. They are just waiting for something new to come on the market.
Agents are just as anxious.
When that new property does hit the market, buyers and agents both will scramble to look at it. It is common knowledge that the property will usually sell for the highest price during this time. After the initial surge of interest, the only people to look at it will be those buyers new to the marketplace. Besides all of the reasons listed above, competition is fierce. You are even competing with the foreclosures in the market.