MLM, multi-level marketing companies are in business and extremely successful worldwide. The majority of these companies are legitimate as they do have products that they sell. MLM in some places and companies are now being referred to as "network marketing" or "affiliate marketing". Wherein the products, goods and services cannot be purchased in a storefront, but directly from the company itself through the brokers or distributors that have access to said products, goods and services.
The concept of multi-level is in everything, all companies and businesses are built around the theme of a triangle or a pyramid. Just as most faiths and religions have a power at the top and then everything else flows under. How many companies have multiple CEOs? The CEO may have multiple responsibilities, but even if there happens to be two CEOs everyone else who works for the company is on a lower level, which in most cases means lower salary.
Granted there are people who will set up scams and schemes and call it multi-level because it is. The pay structure is what makes it be a scam or a scheme for the people who initiated the program. Network marketing should neither be confused with gifting programs that is an entirely different answer and possibly a Hub unto itself.
In network or affiliate marketing, the compensation plan is what makes it be a business just like any other traditional storefront business. When you first get started, you have to start at the bottom, where there may be more work to do and less pay with a lower commission. In network marketing it is entirely possible, according to a company's pay structure to be on a lower level and make more money than the person who recruited you. As you accomplish designated goals, you move up the ladder and the higher levels bring you more responsibility and higher pay. Just like on a regular "job", network marketing just moves along faster.
Network marketing is a multi-billion dollar industry and there are people who have worked hard and have become millionaires and billionaires as a result. Network marketing is a great way to meet new friends and build networking relationships.
The key is finding the company, the product that you like and believe in, which will enable you to be successful, as you will not be nearly as excited about something that you don't believe. You can do research on the Internet to see which company is right for you.