BzzAgent is a product testing panel that I’ve been part of in the past. It’s a very solid company with lots of great campaigns you can participate in. They have been around since 2001 and have overall fantastic feedback from users.
BzzAgent is currently open to people in the US, UK, and Canada.
Does BzzAgent pay you?
You are generally expected to consider your free product as payment because it’s yours to keep in exchange for trying it out and then spreading the word about it.