I invest into bankroll and wait people with "winning" strategies lose their money.
Dont think investing into the bankroll is a sure profit because people can win a lot of money in short period of times making you lose, casinos have it figured it out so they don´t lose money for free when you invest into their bankroll
That's true. Just 2 days ago, a lucky whale shown up on MP and push the investor profit to negative.
But in the long run, the house is most likely going to have a profit close to house edge * total wagered when the law of large numbers kicks in.
There are some other risks, like the house could cheat on investors or the house could lose funds to hackers, and thus you should be careful choosing which site to invest in.