Unique, timeless, flexible these are some of the qualities of a successful logo.
Does it work in black & white? Will it work as a tiny icon or on a billboard?
All these factors and more go into Our Process of creating a visual identity / logo / corporate identity [whatever you want to call IT]. Ultimately IT is the face of your brand. IT never stops working and consistency (seeing it the same way over time) gives IT recognition. So consistency in all company collateral aids the audience in this process and ultimately reinforces your brand and a logo is an essential element to help achieve this, it establishes your brand and adds credibility.