Do you think that company success and it's causes are measurable day by day? I've worked for an industrial company that completely screwed up their software development, but their business is rooted so deep into other businesses, that it would take a decade until the result emerges. This may be extreme, but for average business I would expect 2-3 years for these results to be measurable. Startups may be quicker, but it's extremely difficult to compare them as every startup is quite unique. So if you wait for hard evidence, good luck not missing the train.