Let me think it over.
OK. This one's very common and it's important that you have a good read on your prospect which you should by the time it comes up at the end of the process. Generally what I say here is something like:

YOU: "You know Dave, with what you've have shared with me about
(Repeat his dreams) and the opportunity you now have to do something about it. What is there really to think about?"

The point of this response is to ferret out any remaining objections that they've not yet voiced. If they have them, deal with them and then sign them up. If they're silent at this point, that is, they can't come up with any, say with a smile
YOU: " Right. So why don't we go ahead and get you started. What address would you like to use for your checks when you begin earning them?"

Now if instead they come back with,
"I don't rush into things, I just want to think about it."
Here's where you have to read your prospect. If they're just delaying because they have trouble making decisions, respond:
YOU: "Dave, you're not one of those "tire kickers" are you? No? That's good... then let's move forward and get you plugged in and rolling."

Some prospects are quite serious, yet their personality just needs time to make that decision. This is a judgment call on your part. If they legitimately need time, respond with:
YOU: " Tell you what Dave, I want you to take a day or two and go through the information I gave you again carefully. When you join, I want you EXCITED to be coming aboard our team. I don't want you coming in with your fingers crossed behind your back thinking that you're making some big mistake. Take your time, go through it and let's talk on (Set date & time. ) If you have any questions that come up between now and then, give me a buzz and we'll get them covered."
Bob