Amazon provides global resource assement & access
Amazon is interesting because it dominates online retailing and has automated the back-end with Kiva Systems robots that move shelves to human pickers rather than the traditional method of pickers roaming the warehouse floor. At some point the picking process might be handled by automated arms, but for now human labor is less expensive.
In addition, Amazon was first to introduce a large-scale online work distribution system, through Mechanical Turk. Companies post jobs that can be completed online with piecework pay scale to a worldwide workforce. Since competition for jobs is high, pay is typically low.