It’s a very well-known scam. You cash the check, then they ask you to either wire some of that money back to them as some sort of fee or buy something for them and send the item to them. So, you deposit the check, then wire some cash to them thinking that the check you just deposited will cover that. A few days later, after you already send them the money, the check will bounce and the money you send to them will come out of your own account.
Not a “scam” in the sense of the word, but really not a way to earn any type of money. If you can find the companies that do the surveys and do them on your own with out sites like this you will make a substantially bigger amount of money. The “scam” is they take 90% (if not more, to be honest probably 99%) of the survey payout for themselves. Its the same for the “offers”, they will take the majority of the offer from the company, and give you a small percentage, And if that was not enough, they also take a percentage of your payout. This should be illegal as it is criminal to do this to people.