Azure Stream Analytics brings a unique perspective in the overall complex event processing and real-time processing space with the following customer benefits:

• Low cost: Stream Analytics is architected for multi-tenancy meaning you only pay for what you use and not for idle resources.
• Faster developer productivity: Stream Analytics allow developers to use a SQL-like syntax that can speed up development time from thousands of lines of code down to a few lines. The system will abstract the complexities of the parallelization, distributed computing, and error handling away from the developers.
• Elasticity of the cloud: Stream Analytics is built as a managed service in Azure. This means customers can spin up or down any number of resources on demand. Customers will not have to setup costly hardware or install and maintain software.

http://azure.microsoft.com/blog/2014/10/29/announcing-azure-stream-analytics-for-real-time-event-processing/