I was wondering that too -- I think they get paid on the amount of likes they get and network they receive on their websites, like the amount of traffic they receive throughout the day and how many people are talking about them, then that stems off to companies recognizing them.
But that's if the "networker" chooses to make their website generate money.
Like on tumblr, if a blogger has a lot of followers, they'll change their blog to a domain and put up ads, then generate money from them.
I hope this helps, sorry to go off on a tangent
Makoto Tachibana gives me a reason to get up in the morning