How Much Can You Make from Affiliate Marketing?

I got to thinking about this after watching this video featuring a guy who calls himself ewen chia. I have a web page which is pretty much a blog and has a lot of things on it related to my interests. Of course I am interested in sports, video games, girls, movies and TV shows. So I talk about that sort of thing and I link to interesting articles about those things. This guy was claiming that he made around a million dollars per year, mostly off of affiliate marketing. I would guess that most people would have seen how that works even if you were not really sure of what it means. You will be on a web page and you will see a link and search box for Amazon dot com or some similar e commerce web page. If you use that link to buy something from the retailer, then the operator of the web page will get a commission off the sale. I was really curious as to the basic question. How much can you make from affiliate marketing? Of course for me I would be pretty simple. I am talking about video games, movies and a number of products will come up in the process. You could simply link to Amazon dot come or some other site when you mention it. For example I just wrote a short review of the new Batman game for the XBox One, Arkham Origins. I would just need to link the title of the game to Amazon or some other site, obviously with my affiliate link included. That is pretty common and it would not be that intrusive. I could do that without saying much about it, although I would probably want to explain that I gained something off it.