No limit hold'em poker's extraordinary surge in popularity was partly triggered by the 2004 NHL lock-out which resulted in TV sports channels having hours of empty time to fill. At the same time the game was becoming a very lucrative internet business, allowing cheap and fast readily-available games around the clock. And important, in the world of gambling (online and live), was the ability to play against other humans rather than against a distrusted casino, with all their guaranteed mathematical edge.
As a TV spectacle, since there's so little to see beyond the dodgy baseball caps and shades, poker would have been cripplingly soporific were it not for the innovation of the lipstick camera, a cunning way for the viewers to see the players' hole cards. Thus, the fascinating inner psychological world of body language and emotional response, that's so alluring to the game's participants, is beautifully contextualised. So essentially, for us the viewers, a delicious transparent concession becomes visible; a privilege to which the players themselves are, naturally, denied.
And it's this denial of meaningful information, other than who's winning and losing, that's an integral part of the appeal for the players themselves. Because it allows them to hold on to their most cherished superstitions about themselves and others. See, poker isn't what it at first seems to be: it's not a card game. It's a people game founded on probabilistic outcomes based on severely incomplete data.
It's rather similar to the attractive delusions us guys (typically) have about our alleged skills in the bedroom, or say, behind the wheel of a car. They're beliefs that, reassuringly, can't be challenged because neither we nor anyone else are permitted meaningful means of contrast, comparison, or calibration. It's a perfect breeding ground for zealously exaggerated I-thinks, and when added to the rushes and thrills to be had from gambling and Lady Luck, poker becomes all too irresistible.