Affiliate or referral hunting is hard but once you do able to get up the right method and ways on how to hook up people to register under your link then this is something that could bring out that huge profits into you if those invites would really be all making a deposit.
It is close to a part time to full time job, not something you do out of the blue and end up making huge profits in one day. You have to identify your niche and the audience, what they want to read and SEO this and that. It is a lot of work indeed and not something for a newbie to start right away.
Most people who are successfully doing this are providing something in return too. Like sharing their reviews or making videos or discussing strategies (even if they are bullshit anyway).
That is who they engage the population visiting the site and eventually they convert to referrals.