Doing It for the Art: They started "Good Morning Chia Lincoln" simply because they wanted to. "Good Mythical Morning" is sponsored, but they still do it for the same reason.
Fan Nickname: According to Youtube commenters, the unnamed kid in Epic Rap Battle who Rhett and Link demonstrate the Half- and Full-Nelson on, respectively, is named "Nelson".
Missing Episode: Episode #376, which featured Sam Pepper, was made private and then removed in September 2014. While no reason was given exactly, the fact that Pepper had filmed himself sexually harassing/assaulting women on the streets, plus the ensuing backdraft, probably had something to do with it.