Good-Person
Captain Junkie
Allowing your customers in sampling your products give them enough trust on your products once they tested it and they are satisfy with it. It also makes the review of your product easier for your customers to do since they had first hand experience of the products.
I believe that companies who provide samples of their products to the customers are pretty confident about their quality and this is why they also provide money back guarantee to their customers sometimes. Don't you think?