Some of the reasons are:

Can be run part time.
Doesn't interfere with your normal job
Low cost to start
You already have the office space.
Most training is freely available from the Internet.
Over one or two years of persistent operation a substantial income can be built.

Who can benefit from this kind of business?

Everybody!

Consider these facts:

Doctors, lawyers, and other professionals should have a business like this. It's a kind of insurance against disability, malpractice, or just the desire to quit the stress.

A home based business like this is the best way for everyone who wants extra income or assurance against job loss or dissatisfaction.

A home based business is the best solution for stay-at-home parents or those people who are physically challenged.

A business should be well established for more than three years; five is better. It needs to have a good record with the Better Business and its managers ought to be experienced and respected in the business.

Products need to be affordably priced and desirable. Consumables are the very best items because they bring repeat sales.

Most of all it should be attractive to many other people all over the world. Contrary to common belief a start-up opportunity normally has a short survival time and goes away before anyone can make any money.

A company in business for over six years is a much better choice.

The managers have been successful marketers for over 15 years. I know this because I have been involved in one successful operation which they sold for several million dollars before forming SFI in 1998. That's when I joined this opportunity.