Synovate, one of the largest market research firms, is currently accepting new members into their program. If you are accepted, you will get to try out free full sized products, including toiletries, diapers and more, and also earn rewards for taking surveys.
From what I read, Synovate is one of the best research companies to work with, though I do not have personal experience. Go here to register and see if you get accepted!
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