Have you ever thought why people upload their videos to Youtube? You search anything and you get on youtube easily. Why these people upload videos? What is their profit in helping you get your answers?
Everything is indirectly linked to hard cash indeed. They help you just because they earn money from that. 🙂
How they earn money is what you are thing next? Everything related to earning money online is some way or the other related to advertising and that also works with youtube. You might have seen many ads before your video starts, during the video, be it visual ad or text ad. Numerous companies show their ads on youtube and spend millions just for getting targeted customers like you. If you liked an ad, you would surely go there and this is what they want.
Now a part of the money spent by the company for advertising goes to the person who uploaded the video. It generally depends on the views you are getting on your videos. If you create nice videos, you get many subscribers and more subscribers means more views, and of course more money 😛
Again, earning money on youtube is not that difficult but takes time and you need to have patience in order to earn big. 🙂 So this is how to earn money from youtube easily. Good luck.