Nope. No pyramid scheme and it's definitely not for everyone and there isn't any get rich quick in my business. I'm in the credit card processing business and it's full of people who are more afraid to tell their costumers the truth than the old used car salesman. A person that will do it right can build a good referral business but it's a gradual process and you are an independent contractor, meaning you either sink or swim on your own.
I wish I had a dollar for every one of those salesmen that called on our business......
If all you had was $20K to start a business, it'd have to be in the service industry. Not many barriers to entry and a lot of competition. Hard to differentiate.
I tell my kids all the time: learn how to do something and answer your damn phone! You can make as much money as you want if you'll do those two things. Like Dustin said, I tried for 6 months to get someone to move some dirt around my yard. Finally had a buddy of mine come do it when he was slow.