Low upfront and operational costs are making hosted Web security attractive to resource-strapped organizations. The biggest advantage of these services is the ability to stop malware before it reaches your corporate network. Providers run the gamut from your typical pure-play pioneer, like ScanSafe, to well-established email security service providers. Concerns over privacy, downtime, and latency will impact the decision to move from a traditional security appliance to a software-as-a-service (SaaS) model.”]
Source: https://www.darkreading.com/analytics/how-to-make-hosted-web-security-services-work