mOgliE is addressing a serious point that I have noticed in the past, but didn't want to comment on.
These images (which I see on twitter every few days as well) makes it look like it's really common for gamblers t owin huge amounts of money. In the description, it often says stuff like 'this guys showed us how to turn X amount of money into Y amount of money, which is often not true since most gamblers need to make a huge amount of bets before they even hit that big multiplier.
Promotional as it is, Primedice or most of those casino house who gave this information are doing their best to attract players to use the house and take the chance of winning huge amounts, we do know that facts remains that inside gamblers mindset challenging his luck also appears, trying to build different strategy and allow fate to dictate whether they'll gonna hit the big profits.
All about good advertisement to attract attentions and build positive impressions, that's another unique way to gain more visitors and players inside.