Well, the casino advertised in the graphics part of this spam mail (I got the same) is golden lounge casino, but I'm not sure if the traffic is redirect to them as well as their redirector is misconfigured and throws as 500 Error at this moment.
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, root@localhost and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
--------------------------------------------------------------------------------
Apache/2.2.8 (EL) Server at
www.microgamingcasinossites.com Port 80
I have just received another 24!!!
They seem to come in bursts, and with a dozen or more copies of exactly the same subject line. The subject line changes, and the links go to different domains. If they have 21, I have received about 4 so far.
One is for Microgaming casinos, so if one of these works I will not only be able to identify the casino responsible for allowing this, but also tell if it really is a rogue affiliate or whether the casino have DIRECTLY employed Starzone to do this.
This goes beyond spam, it is a Denial Of Service attack on individual email addresses because of the overbearing volume of identical messages. Because of this, particularly harsh treatment should be meted out to the offender(s).
EDIT
Their website is a fake front.
They are pretending to be a legitimate marketing outfit, but try and sign up as an advertiser or agency and you will find the whole thing is a hoax. ALL links, sign-up, privacy policy, terms of use, etc lead nowhere - they just redisplay one of the bland "about us" pages that tells you nothing. You CANNOT sign up, CANNOT find out about their terms and policies, and as you say, this company hides behind a free gmail address.
They are also incompetent, as even if someone DID try to seek out these hidden bonuses, they will get a 500 error, not 500 free credits.
There is one thing though, ALL these messages have gone to my PRIVATE email address, the one CASINOS know, but that is NOT available for scraping off websites. It seems a casino has sold my email address, and linked it with a data filed that says "likes online casinos", thus it joins the ever traded lists of emails that are good to target with online casino related offers.