By the way, is it quite useful to share our wins or betting strategy?
In my side, it is not really useful. I personally prefer to not sharing anything related to my gambling activities.
Sharing wins may aim to provide motivation to gamblers, that casinos really do pay out winnings. But I'm not sure gamblers need such validation.
When it comes to betting strategies, it may be something that other gamblers could emulate and apply. But we know there will never be a strategy that consistently yields wins for gamblers. Some gamblers won't care much about strategy. They rely more on luck.
If that person wants to sell his predictions to the public, he will share it and convince his target customers. Those people just want to know more predictions so they don't have to bother searching for more just to place their bet. If they can search for more from the predictions, they will find something about the truth. They just rely more on luck or hope from other people predictions. We can not blame them for sharing their predictions. So lets them share as much as they want.