Cloudonomics: The Business Value of Cloud Computing, + Website

Scalability

SaaS environments are designed and built to scale to serve as many customers as necessary facilitating ease of deployment, although in some cases at the cost of highest possible performance. For example, many NoSQL (Not only Structured Query Language) databases can easily scale: Data can be partitioned among multiple servers. On one hand, this partitioning does not always lead to optimal performance compared to indexed relational databases. On the other hand, even if such performance is theoretically not optimal, performance can remain stable even as the number of users or some other metric, such as number of transactions, grows by several orders of magnitude, leading to an advantage for SaaS. Sometimes performance and scale go hand in hand: Most search engines, which are a cloud SaaS solution after all, achieve incredible performance even while serving immense numbers of simultaneous users.