I heard it back in 2011 where in there was a huge hype of mining Bitcoin using GPU's and there were numerous facebook groups where they posted they rigs and also had many tutorials for other to follow or even customize their rigs in order to work better.
Well, I heard it from my classmates a few months ago. Furthermore, my classmates already know what bitcoin is and they gain more money by using bitcoin. After, I heard that I decide to conduct a study about bitcoin because I want to know it well. Lastly, I and my classmates were very happy and we earn money together.