Can't really think of it as starting a job, but as starting your own business. If it indeed costs $500 to become a distributor, I would think that it goes toward that $ amount of product so that you can use it and develop your own health testimony.
As far the negatives you will find on the internet which we all know cannot lie
, you can google most any MLM product that has been around for a while and come up with some disgruntled customer or distributor. Instead of simply owning up to the fact that the product or business just wasn't for them, they would rather get online and gripe about the product or business.