Many employee's work remotely or offsite at least some of the time, and many organizations have multiple locations, which means ease-of-delivery becomes a critical issue. SaaS solutions offer 24/7 access, from multiple locations.
SaaS implementations are streamlined to meet business needs across the board. Multi-tenant SaaS solutions can offer shorter deployment and training cycles. Down time for an upgrade is scheduled for non-business hours allowing for uninterrupted data access.
Since there is no longer a need for on-premise software, the IT department can focus on more strategic organizational initiatives. SaaS frees up company resources, and removes the cost of purchasing and maintaining on-premise software as a concern. SaaS solutions are not the same as "outsourcing" - with SaaS you retain total control and anytime access, with none of the hassles of on-site software.
With SaaS, there is a fixed monthly price per employee. No more costly surprises when an upgrade is needed, which erase concerns about staying within budget.