These schemes offer a tempting increase in income by referring more customers through an investor. In my country there are many vuifor companies who do this business by targeting some people. The reason why Steemit is not considered a Ponzi scheme is because it creates interest in working without the guarantee of money or upvotes. We have to grow up through our own talent and hard work and not by any greed that can make us financially destitute. Thanks for your valuable comments.