At Yahoo, I designed and built a large project. This took about six months to deliver. At the time, the company was doing quarterly reviews that I think Marissa had imported from Google. Anyway, my manager had rated me as "meets expectations" for a few quarters because this project and the one I had previously worked on weren't visible to "customers" till they were delivered, so he didn't have any evidence to justify a higher rating against other managers' team members.
Little did my manager know that a few quarters of "meets expectations" had caused HR to drop me into the bottom 5% of the company and so I received a letter from HR that I was at risk of being terminated.
So I deliver the project and now it's visible and everyone loves it and I get an "exceeds expectations" rating and then a promotion and a raise.
From being warned I'd be terminated to a promotion in less than six months, with no change in my work, but simply it becoming visible. Whee big company fun.