They way it is here, is you give plasma by taking a sample of blood, they take the plasma out and put the blood back in you so you don't become week <End of super long sentence.>. They pay you the first time with $5, then every time you come in you get payed $10 more. They do this until you reach $180. The catch is, you can only give plasma once a month. And you can only collect $180 once a year.
But you have to figure, lets say this takes up an absolute total of 10 hours (it could be significantly less...) That's still $18/hr. Hell yea!