Let's take a look at two typical approaches taken by online casinos. Some gambling sites don't have an official VIP program but if you look closely in the bonus terms or the general terms, you might find a mentioning of better rewards or bigger and faster withdrawals connected with VIP players.
These are the casinos that may invite you to become a VIP player once you've proven to be a regular player who tend to deposit big and frequently. If you accept the invitation, you'll be one of the inundated and can expect plenty of offers.
This can be anything from free spins, cashback, reload bonuses, and invitations to participate in casino promotions. As long as you keep playing at the same level you might get a VIP trip at some point to go see your favourite artist in concert - all expenses paid.
The loyalty points scheme
Other online casinos will have a dedicated section to their VIP program and explain in great details how you can earn loyalty points and what you can trade your points for. Normally, you'll exchange your points for free spins or bonus money with/without wagering.
These casinos are open about what you can expect and you're usually a loyalty member from the moment you start playing with your own money. No casino in their right mind will allow players to earn points while they're playing with bonus money.
Is it all a big scam?
No. It's not a scam, but you should be aware that casinos that aren't open about their VIP programs won't let you know what it takes to become a member. All they ask is that you play with high wagers and make plenty of deposits, regularly. Not a small task.
However, there are many players who use this to their advantage and leverage to get extremely favorable deals since they can always tell the casino that they can take their business elsewhere. Still, you do run the risk of having your membership revoked at any time when there aren't any expressed rules for how to become a member.
The ones that are transparent about how their VIP programs work are often preferred since players will know what to expect. And just because there are terms and conditions, high rollers will know that these are not set in stone.
It all comes down to how much you're willing to deposit and play for. Keep in mind that just because you play for large wagers, it doesn't mean that you'll necessarily lose faster. You'll have the same probability of hitting epic wins to blow your bankroll through the roof, but don't bet on it.