Not everyone decides quickly, and many, if pressed will back away or react against the sales methods being used. Decision-making is often a complex thought process where pros and cons are weighed up and the person may not decide until they have gone through this process. This is particularly common in sales which involve significant money or other commitment.
Sometimes it just takes a little time to sink in. You have given them a lot of information which they need to process it and fit it in with their current models of the world. Read about using this process to close business here.