One of the first impressions a prospective Buyer will have will be based on the fragrance of the house. The most immaculate home will be looked upon unfavorably if there is a lingering pet odor or unsavory mildew scent that permeates the building. Oftentimes, pet odors can be eliminated by replacing carpet padding after a thorough carpet steam-cleaning while mold or mildew scents are eradicated with detailed cleaning of basements and air ducts. Whatever the source of unpleasant smells, the point is to target and destroy them, before they affect your potential bids.