These are some of my favorite "word of mouth" companies. These companies send you full-size products and all they want in return, is for you to tell other people how you liked it.
BzzAgent is a GREAT site for getting free full-size products and services to review.
The more you "bzz" your opinion about the products and services you try, the higher your "social status" gets, (which means you get earlier invites to campaigns). You also get MyPoints points each time you submit "bzz" or do an opinion survey, (usually less than 5 minutes long).
I have done countless product reviews for them and I love them. You always get full-size products and the services they offer are wonderful. This is one of my favorites.
Crowdtap is a good site for sharing your opinion on products. I did a couple of product reviews through them, including Playtex Sport Body Wipes and Old Navy Active Wear Pants. I also did one about Old Navy Summer Shorts and Woolite! I am loving it! You can also earn money for yourself, (in the form of Amazon codes), and for a charity of your choice. Points and cash build up quickly and you can cash out at $10.
Houseparty is a great site. You can apply to host one of their houseparties. If chosen, you will receive a party pack with things to host your party. It's awesome.
One2One Network is mostly for bloggers. It has lots of opportunities for sponsored posts and reviews. Sometimes there are small $5 prizes for being one of the first 100 people to do the required posting and then there are usually quite a few prizes, in which, the winners are drawn randomly. I've been a member for quite a while...years...since, like, 2006 or so. I absolutely love it! They have lots of opportunities for reviewing new albums. You get a digital copy of the music album and then review it. There is usually a prize for early prizing as well.
RewardSurveys is great because you can earn free magazine subscriptions. Good ones, too. All you do is sign up and every week, they will send you a survey in your email. It takes like 5 minutes to finish and then you have $30 in your account you can use to get a subscription to a magazine. I love it.
Smiley360.com, (formerly Smile.ly), is a cool site that sends you full-size products to try out and keep. I have done a couple of missions for them so far, and I love it. You get products by signing up for "missions" that they offer you.
Be sure to fill out your profile so that you get offered the missions that are right for you.
After you accept a mission, you can earn "smiles" by sharing information about the missions. For example, you can share on Facebook or Tweet that you accepted a mission and they are sending you free products to try. You usually will get coupons to give to friends also.
There are lots of features, so be sure to look around at everything once you sign up. The higher your status gets, the more missions they offer you.