SamplesZing.com are dedicated to finding the latest and greatest freebies and free samples. They personally sort and try the free products online and coupons to reassure that all the deals are legit.
Companies give out free samples by mail all the time, it's a very effective marketing strategy. If you like their products there is a good chance you will buy from them in the future. Many big retailers and manufactures have budgets in the millions of dollars just for giving out samples of their products.