Our assessment is that the cloud market, internationally and nationally, is not sufficiently mature to ensure that we could pick a single cloud provider now, noting that such a contract would probably need to run 5-7 years, and be satisfied that such a provider would stay at the leading edge of the market in both the technology and commercial senses to ensure the model would work.
For example, Amazon has dropped its cloud prices 42 times in eight years
http://www.businessspectator.com.au/news/2014/3/27/technology/amazon-drops-...Technology is also changing - the graph shows a portion of Google's average PUE improvement over time -
https://www.google.com/about/datacenters/efficiency/internal/