You can take 2 approaches. You can be the a**hole seller who seller who makes enough money that he doesn't have time to deal with the little people who ask too many questions. Or you can be extremely humble, polite, and patient and give it your all to get/keep each customer and make them feel like a special little flower. I've seen it done successfully both ways, though most lean toward the latter, and some of the former aren't actually making that much money and the attitude comes naturally. It really depends on how many sales you're getting. There are people who say a certain amount of your time is spent on a certain percentage of your customers (can't remember the figures), and if you cut that percentage off you have more time to grow, develop new projects, and help the rest of your customers. It's a reasonable theory, but not a good one to start out with.