Visitors want familiarity.

One of the single most important aspects of effective navigation is consistency. Why? There's a simple reason.

Visitors want familiarity.

They are more comfortable and more trusting if they know things are going to remain the same from page to page. They have a certain sense of confidence from knowing what to expect.

If a visitor can quickly become familiar with your navigation, it's much simpler to actually navigate. And of course, that's the whole purpose of navigation, right?

Besides familiarity, there's a second reason to be consistent. It helps your credibility.

Consistency in your navigation helps you present a unified, cohesive image to your visitors. In other words, you look polished, well-thought-out, and on top of things. Your visitors get the impression that you "have it together".

On the other hand, if your navigation is inconsistent, it reflects badly on you and your company. You'll look disorganized and unprofessional.