The ones that are generally are called Franchises. The value in a franchise is that it comes with branding already done for you. People will recognize a Subway or McDonalds no matter where you are, so you have a built in customer base.

Be it Amway, selling jewelry (and other products) on a party plan, vitamins that you have to invest in a ton of inventory to carry around, or door to door knives scheme that costs $500 to join, each and every one of them makes their money off people looking for opportunity, not from products sold to average consumer.

Very few people ever make any money with these so-called 'business opportunities'. I've personally never met even one, though I've known many people who have gotten involved in these businesses. All of them spent more than they ever made back.

Seminars are worst. Sometimes they call them boot camps. Come to our seminar and we'll show you how to make tons of cash.

Do you feel that you must, because idea of not trying is infinitely worse than idea of trying and failing?

Can you afford risk? Do you have either a good backup plan, or is your present situation such that you don't have real responsibilities (family, children, mortgage) to take care of?

If you do have these kinds of responsibilities does your plan allow you to continue in your present occupation until new venture takes off?

Are you willing to fall down (fail) and get right back up again, brush yourself off and move on, perhaps several times before ultimately reaching your goals?

Are you willing to spend many long hours - for six months or more - doing potentially thankless work with great enthusiasm for potential it represents?