Service oriented architecture (SOA) and Software-as-a-service (SaaS) are a perfect match for businesses wanting to blend external services with internal assets. SOA would be essential if a business is to adopt SaaS to ensure that the service will adapt to the needs of the operation. SOAs would benefit from SaaS to get composite applications without pressure on the development side. It is expected that 25 percent of business software would be SaaS by 2011. However, for SaaS to be really efficient, a steady SOA model is important in seamless integration. The SaaS market is dominated by such players as Salesforce, NetSuite, and RightNow. Those with lesser customers are engaging in SOA to attract customers demanding subscription-based software. In time, it becomes more difficult as more customers ask for scalability and flexibility. RiskMetrics, which offers financial risk analysis software, is one company that is transitioning to SOA. The company believes that SOA will help it build various configurations based on customer preferences. WebEx, a long-time provider of online meeting application, counted on SOA to effectively launch WebEx Connect. SOA was elemental in WebExs aim to integrate on-premise resources with its collaborative applications. There are issues that come with SaaS deployment, including the challenges that will mount as businesses create enterprise mashups. For SaaS to be a major element in software delivery come 2011, such issues must be resolved.