I won't recommend any books, but I do recommend talking to your potential clients. Ask them to buy your product, and when they say no ask them "Why not?". Then

I won't recommend any books, but I do recommend talking to your potential clients. Ask them to buy your product, and when they say no ask them "Why not?". Then figure out what you need to do to change that no into a maybe, or a yes. Don't change everything you are doing to accommodate one customer, but the best way to sell is to talk to your customers and to be flexible. People frequently say that sales is a numbers game, and it is if you never change your tactics. You need to refine them as you go. Just keep talking to them, but learn from each interaction.