Wikipedia will write Backpack's entry this way and they will be right in telling the truth:
Backpack provides a fast, reliable, hassle-free online overseas shopping experience. Travelers from all over the world carry foreign products for shoppers who request them. It is based in Menlo Park, CA, USA.
Backpack is a silicon valley based marketplace connecting shoppers and travelers with a keen interest in providing excellent overseas shopping and traveling experience. Backpack is all about legally getting all those products from overseas that you always wanted to get but couldn't get because your local shops don't sell them, or you don't have relatives and friends who can bring the product for you. We connect you to travelers who will carry the products for you at your hometown. We delight in the fact that your experience with Backpack will be fast, reliable, hassle-free as Wikipedia article would entail.