Each Cloud Segment Has a Different Leader

At least so far, each of several cloud services segments seems to have a different market leader, with the caveat that what one means by "cloud" service can vary.  

Cloud infrastructure service revenues grew 15 percent between the fourth quarter of  2011 and the fourth quarter of  2012 to reach USD$12.5 billion. 

Amazon continues to lead the infrastructure and platform as a service portions of the cloud  services market.

While revenues associated with the IaaS and PaaS segments account for only 15 percent of the overall market, over the past yea IaaS revenues grew 55 percent while PaaS revenues grew 57 percent

The more mature managed hosting part of the business grew six percent (some people might not classify traditional hosting as a cloud service). 

The co-location segment grew 13 percent. Combined, co-location and hosting account for 74 percent of total "cloud" revenues. Synergy also considers content delivery networks part of the cloud services market. 

Not all observers would consider either hosting or colocation, or content delivery networks, to be part of the core cloud computing market. 

Cloud Infrastructure Service Market Leaders by Segment, Q4 2012

Source: Synergy Research Group/TeleGeography