Yip, that’s pretty much how it works. If you see at the bottom of a column the tipster telling you to back it with a certain bookie you can be fairly sure it’s an affiliate link.
Also if you were a pro-gambler, it would make sense to sign up through affiliate links that you may either control or could be in cahoots with. You could be ensuring yourself for up to 30% of your losses.
But say you were a blogger/website you heavily promoted skybet on your website at the expense of other bookies, you are going to pretty pissed off now if SkyBet say tough shit, we are keeping the customers you sent us, but you are getting fuck all for it.