Let's say you sell AAA memberships. Chances are the person does not have a car problem right now while you talk with them. However, suppose you get stranded one cold dark night. Now, we are not suggesting to nag your prospects like a little child, but you get the idea. Don't take my word for it.
Testimonials are one of the most powerful ways to persuade someone.
Don't give a presentation, and then ask them for a decision. Let them make small decisions first. That helps them make the big decision later on. The trick to successful persuasion is knowing when to talk and when to remain quiet. It might feel uncomfortable for you, but it gives the other person time to make the decision.