A logo is a visual associated with your name that people will use to reference and recall your brand. Our minds are visual first, so your logo is meant to visually create a cue to associate and remember your brand. This means that the perfect logo should be focused on that very concept. Making it as easy as possible to see,read, and remember. The best way to do that is to make it proportionate to the eyes. So, if you were to take your logo, and overlay an image of someone's eyes, the logo should fit that shape perfectly. This way, a person can process the logo without even blinking. The approximate proportions should be 1 x2.25, think about the average size of a billboard, or a perfect example is Avis's logo. IF you are wondering if you have a winner, close your eyes, and open them. Did you process the image immediately or did it take a second. if you had to adjust your eyes, it doesn't fit the eyes. If not, you have a winner.