I am sure he is just saying that because he thinks it is true.  He's never owned an online casino.  And there's the biggest different between this jokester and me - if I don't know, I won't say a word.  I don't know if casinos operate differently from other PPC (pay per click) or pay for placement (rent space on a site for a banner) advertisers, so I won't comment.  But I do know SEO, and given that Axel came in here and spouted some nonsense about "how easy it is to manipulate Alexa rankings" I have to assume that he may have no idea what he is talking about here too.
Just spending a few minutes of research I found this article
The Cost of Google Adwords
for Online Casino's
https://www.sayu.co.uk/the-cost-of-g...e-casinos.html
which outlines the PPC cost of casino advertising online, and just the existence of this article contradicts Axel's claim that online casinos will not pay per click for advertising.