Software-as-a-service (SaaS) CRM vendors are pushing on an increasingly open door in selling their products. Based on vendor revenues and growth, we estimate that the market for SaaS CRM was around $900 million in 2006, and we expect it to be around $1.3 billion by 2010. At some time the door will have opened to its full extent and there will be a slowing of growth, but there still appears to be a way to go before this occurs, especially in those markets that are currently least accepting.