They might think you are a buyer and launch into their own sales pitch thereby continuing the conversation and giving you information that allows you to qualify the business. Get initial interest and trust, and then turn the situation around to ask questions. Ask Questions , be quiet, and listen. Don't be so quick to sell. The best sales people listen more than they talk .
People relax when they hear the sound of their own voice.
People enjoy talking about their jobs, their passions and their businesses. Give me a good reason why our two companies should not be doing business together, and I'll have a good reason for my boss when l'm asked why I didn't get your business. Then I can quit bugging you with my phone calls. Most of the people you call on are managers themselves and understand that you have a job to do and must report to someone. Try to find a reason your customer won't buy.