Those who charge for Tarot/fortune telling

Just curious—what exactly does the fee cover? Does it include tools, resources, or any kind of guarantee?

Is there a standardized training program you go through to ensure reliability? Or maybe a certification or governing body that verifies the accuracy of your predictions or whether you are following the guidelines of your trade.

How do you measure success—by actual accuracy, or is confidence the key? And what happens if the predictions are off?