Not just Microsoft, any company that has a size greater than three digits.

On average, at a big company, you're going to spend 95% of your time interacting with less than 1% of the employees.

I dunno. Numerically that seems right - Google has 30k+ employees, and I definitely spend 95% of my time interacting with less than 1% of them.

But I've found that the breadth of interactions in that remaining 5% reaches across a wide expanse of the company. I work in Search Features. I have friends and professional contacts not just in Features, but also in Ranking, Maps, Glass, Google+, GFiber, Chrome, Android, AppEngine, YouTube, Research, Brain, CourseBuilder, Doodles, legal, and PR - not to mention a whole bunch of infrastructure teams and research projects that I can't tell you about.

And I've found that one's effectiveness in a big company is to a large extent dependent upon the breadth of your internal professional network. The folks who seem to shoot up and don't get pigeonholed into just writing code for their manager are the ones who have a wide network and always seem to know somebody who can get this thorny task done.