A company logo is a powerful thing which can communicate the ethos of a brand in an instant. But how do you know when your logo has hit the mark and will resonate with customers? And, at what point do you need to think about giving one an update? C+R Research tracked how logo evolution relates to revenue for some of the most iconic brands in the world. The market insights agency made some interesting findings. Microsoft, for example, grew its annual revenue by $73.3 billion using a single logo between 1987 and 2012. And the last time Amazon changed its logo was 2000. Since then, the company went from being merely an online bookseller to one of the most powerful companies in history. Check out this infographic, which details how more than a dozen famous brands have changed their logos over time and what it has meant for revenue.