How to measure ROI on BI applications

I’m excited to see Boris Evelson’s excellent Blog post on measuring ROI on Business Intelligence application. He has listed out the key data points (Usage Tracking, Efficiency & Effectiveness) to collect/track in an organization and also mentioned about how these data points will be helpful for defining action items and planning future BI applications. I’ve seen some BI implementations with little or no insight on ROI and continuing the BI implementation endlessly. Though it is difficult to collect (automatically & painless) the data points that he mentioned are really informative.
In SaaS environment , Self service BI & Response time are really key items and measuring the same would really helpful in assessing the SaaS based BI applications.
Here is the URL of the post http://blogs.forrester.com/boris_evelson/10-04-05-bi_bi