Typically a white, american, suburban, middle class teenager with below average social skills and an obsession with certain children's books/tv series/and video games that they maintain well into their twenties and thirties (probably longer though it remains to be seen).
To give them credit, they have managed to achieve things as a group. Most noteworthy being, raising money and awareness for many charities during the Vlogbrothers annual 'Project for Awesome'.
However, they are unable to describe these achievements as 'doing something good' or 'being a nice person' like you would expect. Instead they like to employ their pretentious, irritating and painfully unfunny catchphrases 'decreasing world suck' and being 'made of awesome'.
Ultimately they are harmless people, who try to do good in the world but go about it in the most obnoxious, styleless and cringeworthy manner I have ever had the misfortune to witness.
Normal Person: Yeah, I volunteer at the Homeless Shelter on weekends.
Nerdfighter: Thats so cool, you are made of awesome! DFTBA man! Lolol don't you think I'm quirky and adorable?
Normal Person: I'm going to leave now.
Nerdfighter: *goes to write quotes from a John Green book all over their shoes or some stupid shit*