What is the best question to ask a prospect?

"What interested you enough to request more information?" That is the golden question. Watch what it does. It reminds them they took action, so this is not a cold call. It hands them the microphone, so you can listen instead of pitch. And their answer tells you their real motivation, the actual reason they might buy, in their own words. Everything you say after should connect to whatever they tell you. One question, and the prospect draws you a map. Ask it early and often.