Casino's are just doing that to attract more gamblers, why not they try to show the losing stats of their gamblers.
I guess that will make other gamblers upset to show their lose, but showing up the profit of gamblers to their stats, that's encouraging people to gamble with them.
I think that is one of the strategy of a gambling site to attract more players. And almost of them display it for good. But does it really shows a legitimate stats without disguise?
Whatever strategy it is used in betting, you can't apply it in all kind of gambling. It might work in a particular game but not with the another.
Yes it is a marketing strategy of casino's to attract a lot of gamblers. Why would they humiliate their gamblers if that is one of their main source to keep the site running. And for the strategies, as long as you are getting positive result with your very own strategy just keep on going. If you think that you are safe with that method, go on.
Definitely they will ensure that they can retain their players because these players if having a good experience in your gambling site will invite their friends to gamble as well, the more they can attract gamblers the more they are profitable, so the promotions are still going on.
The support is very important also and they make it the best to compete with others, you see what the qualities of a good gambling sites, they don't let their gamblers down as simple mistakes will make big impact on the business operation.