In a recent report on Green IT, McKinsey surveyed data center usage and expected growth in the next years (download the full report for free here).
More efficient hardware, optimized racking and virtualization can do a lot to cut down in inefficient hardware use that is prevalent today. Still, CO2 emissions from data centers are projected to go up fourfold by 2020!
While Workday certainly has an already very efficient use of our data centers, our current customers might see us as an opportunity to reduce their energy costs more rapidly and cost effective. In the end, SaaS is green!