AppNana

A very successful pyramid scheme. I'm surprised how nobody else caught on.

You sign up. Usually because your friend gets you to put in his code. You do that and gain 2500 nanas. Now, you want some points, so you get 5 people to put in your code, then they get 5 people to put in their code. Because you can put in a code every time, 5 people put in your code, it is horribly unsustainable.

Using exponential calculations, you will need more than the world population to be able to put in some else's code 15 times, and that's assuming everyone will be willing to do that:

1
5
25
125
625
3125
5625
78125
390.625 Similar population of a medium sized city
1,953,125 2/3 of Greater Manchester's population
9,765,625 Similar to Sweden's population
48,828,125 Almost twice the Australian population
244,140,625 More than the United States population
1,220,703,125 Slightly less than the population of India
6,103,515,625 Around 1.5x the population of Asia
30,517,578,125 Around 4 times the world population

Pyramid schemes are illegal, but they are very smart about this. They don't get you to pay with money, they get you to pay with your time.

My friend: What's up? I got this cool app which lets you get paid apps for free! It's called AppNana.
Me: You've been scammed.