Casino gambling in general and online casino gambling in particular is a negative long term EV activity. All reasonable gamblers know that and they all know why it has to be that way. People are generally aware of the house edge as the main tool the house has at its disposal to generate revenue. The house would simply not be able to offer players any of the games it does, if it weren't for the house edge. Most players view the house edge as a necessary "evil" and they have learned to cope with its existence. Most casino gamblers also know that online casinos can afford to give players smaller house edges than live gambling operations. The smaller house edge will not show up at the table. A game is a game and it's the same both online and live. The smaller house edge comes about on account of the various promotions and bonuses offered by online casinos. A rakeback-like loyalty bonus will offer players a long-term and ever-lasting rebate on all the revenues they generate at the casino tables. Why can't live casinos afford to give you such perks? The reason's simple: the operating costs of a live casino are infinitely higher than that of a similar online operation. These guys need tons more money to keep their business running, therefore they cannot share their revenue with their players in any shape or form.
As I said above, most gamblers know all this and they fully accept the situation, with the serenity of the experienced one who knows how and why things are supposed to click. The problem is though, that most of these people don't actually know the real mechanisms behind the revenue-generating engine of the online and live casinos. The house edge is not the biggest menace towards one's bankroll, though it is definitely responsible for it. The real culprit here is the house drop. The house edge serves merely to induce the house drop, but as such it is indeed the root of all problems. While the house edge is usually an extremely small percentage (some slot machines feature a house edge of 1-2%), the house drop can be as big as 30%, or in some cases even 100%.
Here's how the house drop works: you walk into a casino with $10, with the intention of placing 10 $1 bets. The house edge on your game of choice is 5%, which means that on average, you lose $0.05 on every $1 bet that you make.
After 10 bets, your losses amount to 10X0.05 = $0.5 which does indeed represent 5% of your bankroll, properly reflecting the effects of the house edge. After your first 10 bets, you're still left with $9.50 though, so suppose you decide to hang around and bet some more. You place 10 more bets after which you lose another $0.5, which leaves you with $9 in your bankroll. The $1 total loss though is no longer 5% of your original bankroll, but rather 10%. That there is the house drop in action. If you keep on coming back until you run out of money, you'll drop your entire bankroll, accounting for a house drop of 100%. Now that you know how things work in casinos, you have yet another reason to move your gambling online. Sure, the house drop exists online too, but given the much smaller house edge and the various loyalty bonus deals, it'll hit you in a much less obvious and painful way.