How does someone obtain permission to stream games?

Here's a question I've had for a long time and I never really could find an answer, even with the help of the all knowing Google.

How does someone get permission to stream and make youtube videos with/of there favorite games? I know you're supposed to contact the creator and get written permission, however the only way I understand to do this is to pay a fee to a company to do this for you.

Is there anyway little Timmy on youtube with ten cents in his pocket can get permission to make a fallout 3 play through series and earn (a very low amount of) money off the partnership program?

Thank you for your time and consideration. :) I hope everyone who wanders through has an awesome day.