If some of the gamblers are here only for fun and entertainment that means, this type of gambler is willing to take risk and can afford to lose, it doesn't matter for if He win or lose. But if you are here in the gambling to earn a lot, you need to have a good plan or strategy to beat the beat the house edge something like that based on my experienced.
They also need to ensure that they gamble what they can afford to lose, and having a plan is not something we have to continue to remind then as for sure they already have that since the words " to earn a lot" means you are into business to make money, hence treat it as a job.