A handful of website portals over the year taking ad money from competitors are owned by online gambling sites. I was always told that WinnerOnline was owned by an online casino - not sure if that is the case or still is the case. TheRx.com is owned by Marty Jensen, who in turn owns several online casinos (many of which were long considered "rogue" for bonus confiscation).
I'm not saying this is right, just that it is nothing new in this industry.
Actually This Is Quite Common