Logic Reasoning and common sense-where are they?

Everyday I see people online that do not use their intelligence.  They jump into programs that would be revealed for the scams they are with just a little bit of logical thinking.  A little bit of investigation would cause them to fall apart.

For example, can you do math?  Tell me how you think you can pay $20 to join something and earn millions off that one time $20 payment?  If 1million people join it yes they have collected $20 million but don't you think when they divide that $20 million your share is going to be $20?

Or the hype page is screaming how you get 'free' money just for joining. And you are earning 'free' money when you recruit someone who is also earning 'free' money.  Have you read the Terms of Service.  Does it say in that TOS That you are specifically earning that money in USD or other legally recognized tender in the TOS or does it say you are earning some form of doggie doo dollars with no set cash value?  If there's not set cash value what are those doggie doo dollars worth?  Well it said it should be comparable in value to USD.  Do you understand the meaning of the word should?  that does not mean that the value is the same.  If you take the time to read you will see that they always give themselves an out.  A way to value those doggie doo dollars as they see fit.

It's based on cash 'gifts' and you you electronically sign a disclaimer that you do not expect anything in return.  Oh really, then why are you joining it?  Because you intend to make money by receiving 'gifts' from others who join under you.  Never mind the fact that people are guaranteed to lose money that they can probably ill afford on a pipe dream you have sold them.  

It's not rocket science.  It's plain common sense, something we were all born with but we don't all choose to use.