Chances are that after going to a bunch of houses, you will hear certain similarities in disinterest. Keep an eye out for these basic themes, and prepare answers. You may not always get past them, but you will be prepared to address some early concerns. A negative buyer can still be open to persuasion. Don't see those negative responses as refusals, but as opportunities to give more information. Your potential customer needs to know that what you are selling will give them something they want. You should know the difference between a "benefit" and a "feature." A feature is something your product does, such as a vacuum that picks up more dirt than its competitors. A benefit is what you get from that feature. For that vacuum, the benefit would be a cleaner, healthier home. If your potential customer seems unwilling to buy, let your enthusiasm guide them. If they can't believe that you like or believe in your product, why should they? Most people will not want to stand in their doorway for too long, so if there is an opportunity to talk further, they will generally invite you inside. If possible, try to get contact information. With that, you can always offer to come back or call at another time. If you have fliers, business cards, or other printed materials with your contact information, this is a good moment to pass them out. If you don't have any, it might be good to get some. If a person gives you a direct "No" in response to your offers, thank them for their time and move on to the next house. There is no benefit to pushing that person any further.

Summary:
Learn the common negative responses. Focus on your product's benefits. Be positive about your product. Offer to provide more information. Pay attention to clear rejections.