Software-as-a-service (SaaS) has grown far beyond the initial offerings that presented little or no customization or integration. Leading SaaS vendors now provide a platform that firms can use as a hub for multiple third-party technology solutions and custom-developed add-ons. However, the SaaS platform market is still in its infancy. Firms looking to invest should proceed with caution as vendors work out platform licensing, support issues, and growing pains that come with opening their platform to multiple development shops and third-party vendors.