Website buttons always need to suggest clickability.
We’re not saying all buttons on the Web need to look exactly like physical buttons, (We love ghost or line buttons) but flat buttons require consistent placement, shape and color to be effective and suggest a real world button that reflects the user’s mental model.
Visual cues that align with people’s expectations help them quickly determine which items to click on, nothing frustrates us more than clicking on something that looks like a button or styled link and nothing happens.
Our users need to know which areas of the page are plain static content, and which areas are clickable, otherwise you run the risk of them going click crazy for a second or two and then clicking away from your site never to come back.
There is so much more to mention about button design and placement, this post detailed a couple of hints to avoid disaster, when its comes to navigating around a website.