Then online casinos are a bad business and shouldn't exist, just like breweries shouldn't exist if they can't break even selling to casual drinkers and need alcoholics to make a profit, and gun manufacturers shouldn't exist if they can't break even selling to one-or-two-gun owners and need wannabe-commandos and survivalist cosplayers to make a profit.

Acquisition cost is basically an auction. Different casinos try to outspend each other on advertising. If the lifetime value of an average customer trends down then the acquisition costs will come down too.