You can expect to earn $2-$5 for most of the surveys in general. For some special surveys you can earn up to $50 per survey but those are rare. Harris Poll also conducts paid focus group studies where you can earn $50-$100 per study. Usually these focus group studies are 1-2 hours long where you interact with other participants under a supervision of a focus group moderator.
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.