I just happened to read Tobias Meyer’s insightful article: http://agilethinking.net/essence-of-scrum.html and suppose describing the results of teams/organisations doing Scrum would be an useful addendum.
The primary benefit is significantly better productivity, but there are a handful of other important benefits(possibly even more important):
2. Higher possibility of building the right product
3. Speeding up learning, which increases the rate by which previous benefit is accrued.
Coming back to the topics of productivity, I’ve personally helped teams increase it in the range of 30 to 60% and am convinced that those teams can do even better. So the claims of a 200% increase in productivity by some others are not necessarily codswallop. (However I’d caution against productivity becoming the MAIN/ONLY goal of adoption.)