"There is more than loyalty at stake for Atlanta-based UPS. This year, its Amazon account exceeds $1 billion. ... The average cost to handle a parcel was about $8 last year." [2]
"Some analysts say the move could help position Amazon to offer shipping services to other companies, eventually competing with the likes of United Parcel Service and DHL Worldwide Express. ... Amazon rolled out thousands of its own trailers and launched an Uber-like delivery service last year to handle the so-called last mile of delivery, taking packages from distribution centers to customers' homes." [3]
1: http://www.marketwatch.com/mw2/palm/marketwatch/story.asp?gu...
2: http://www.nasdaq.com/article/amazon-seeks-to-ease-ties-with...
3: http://www.nbcnews.com/tech/tech-news/amazon-drops-hints-it-...