No, actually I learned that from following my gf's notes during the time she was earning her Master's degree. Working for pay is one of the most popular examples of positive reinforcement as it's something that everyone who studies any type of conditioning can relate to.
Ask Mort about it, or go read some wiki
https://en.wikipedia.org/wiki/Reward_system
fair point, paycheck is positive reinforcement...not in a classic reinforcement sense as it is quite removed from the action itself, but the older one is the easier they can link two events that are not linked time-wise