Such organizations seldom involve sales of products or services with value. Without creating any goods or services, the only revenue streams for the scheme are recruiting more members or soliciting more money from current members. The behavior of pyramid schemes follows the mathematics concerning exponential growth quite closely. Each level of the pyramid is much larger than the one before it. For a pyramid scheme to make money for everyone who enrolls in it, it would have to expand indefinitely. This is not possible because the population of Earth is finite. When the scheme inevitably runs out of new recruits, lacking other sources of revenue, it collapses. Since the biggest terms in a geometric sequence are at the end, most people will be in the lower levels of the pyramid; accordingly, the bottom layer of the pyramid contains the most people. The people working for pyramid schemes try to promote the actual company instead of the product they are selling. Eventually, all of the people at the lower levels of the pyramid do not make any money; only the people at the top turn a profit.