I'm sorry because I didn't know where else to post this. I've been selling Google cloud accounts and I got contacted by someone saying they'd like to purchase 100 accounts. I told them they would take at least 2 weeks as it takes me a while to get them. Anyways fast forward 2 days and he says he wants to pay right away. I told him that I just had 44 at the moment and therefore he should pay only for the accounts I have to avoid the stress on myself of getting him the other 56 accounts on time.
He made up some bullshit story about how his account got hacked and he wanted to deal with me by sending me btc on Chartrade.com. I found this odd but I said okay. He sends me funds on Chartrade.com and when I tried to withdraw them, it asked me to "verify my address" by sending 0.02 BTC to the exchange first. I found this very funny so I told the guy about it and he acted surprised as if he didn't know what was happening. I realized that this was all a very clever, creative and elaborate scam and told him to go screw himself with his scamming BS. He blocked me after that.
So basically you might be contacted by someone who will try to buy a ridiculous amount of your goods or services and tell you they want to pay through an exchange. They'll send you the funds on this exchange (Those funds don't actually exist because they own those websites so they can just create 10000 BTC in the exchange database if they want to lol) and then the exchange will require you to deposit a certain amount of crypto before you can withdraw. The moment you deposit anything, you will be scammed lol.