What is a early release link? How does it work?

I've heard a lot about these links because the if the prelude packs. How exactly does someone get their hands on these links? Wouldn't the person who got this link have to work for Nike or know someone who does? Please can someone shed some light on this. 

dont worry about it lol. not even worth it really, today's EL failed. hope more people actually start getting banned for using them, which likely will happen anyways