RAX's strategy has shifted to "different segments" directly as a result of competition from AWS [0]. Now, AMZN has considerable supplier power over RAX:
"The deal would have been unthinkable just two years ago,
when Rackspace and AWS were fierce rivals. But in early 2014,
Rackspace, facing ever slimmer margins amid a cloud-computing price war,
withdrew from head-to-head competition with Amazon. Since then,
it has focused on offering higher-margin services."
[0]
http://www.wsj.com/articles/rackspace-teams-up-with-amazon-1...