A must-read for anyone interested in the lean thinking. It builds nicely on top of heavy-weight books about innovation like Innovators Dilemma and Crossing the Chasm, but it more of a manual then warning. As companies, big and small, try to be more nimble and start-up-like in order to stay ahead of the competition - read: ahead of disruption - the lean & agile approach helps orient planning and action. A lot of companies are on this path, now it is a matter of how successfully they can implement.
Ries' manual is an easily digestible read. I appreciate him assuming the reader has already bought in to the lean approach, which allows him spend more time on action than on convincing why lean works.