Even if we know that the gambling site is fair, it won't affect the fact that we still lose more in those sites than win. But it's not that useless of an addition, at the least we know that the sites we're playing in are fair, right?
It is true that most of the result when we gamble is always lose. Only fool will think that the win are more than lose. Not all gamblers are gambling just for a chance to win big time as some gamblers are looking for fun, excitement, thrill and more. Well yeah, at least the site is fair so those who are looking for fun won't be a problem.