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.
In what ways are you expected to spread the word?
BzzAgent wants you to tell your friends and family about the products you try — sometimes they even give you more free samples or coupons for the product you're evaluating so you can share with them. They also like for you to share via your social media accounts — Facebook, Twitter, whatever you use. If you have a blog, they like for you to blog about the products you get. Just anything you can do to spread the word is good!
How often do you get campaigns to participate in?
It will vary. Just keep tabs on your dashboard to see if anything new pops up. You may also get emails from BzzAgent if there are new campaigns you might qualify for. When you sign up, make sure you fill out your profile as completely as possible so they will have a better idea of what programs you might be a match for. They also of course want you to connect your social media accounts to your BzzAgent account, but this is optional. However, it would make sharing your feedback on products you try via social media a little easier for them to track.
My Experience With BzzAgent
I have not participated in BzzAgent for a few years now, but I've gotten in on campaigns before and received generously-sized freebies to try out and spread the word on. I have no problems recommending it to others.
How can you sign up to be a BzzAgent?
Interested in more product testing sites? Go here for a list of several others.