As far as i have researched i guess the op is talking about Facebook Audience Network unless i am entirely wrong but if i am correct, this business is very legitimate and can earn you a lot of cash.
@ OP, you need someone to vouch for your product and i am available to write a comprehensive review about this business provided you can send me a vouch copy.
I felt like he is talking about Instant articles but it is not so successful platform on facebook as many of the advertisers taking back their ads from it recently. 600$ - 1300$ per month looks too good to be true to me.