Storm token is trying to compete with Amazon's mturk, Amazon currently has to pay some users with gift card or Amazon credit. So maybe they need another alternative
Amazon is involved in a couple rumors when it comes to cryptocurrency. They have lately been said to introduce XRP as a payment option as well.
About Amazon use XRP, If it is not a speculative rumor that started since last December so it can be called as just "get rich quick" scheme from XRP holders. There is no official statement from the compagny. Besides Storm is not really trying to compete with amazon because it already has it's own unique business model. Price of storm should be rise again by completing the next stage in roadmap.