Visual hierarchy adds beauty and order to your design. It offers to your eyes visual assistance, suggesting to them, what information to linger on to, as your vision glides through it. It lays down a path for the data to flow in, to get absorbed into the brain smoothly. It guides the human eye from one element of the data to the next, like an invisible pointer moving through the data, to keep the reader free of any visual fatigue. Adding hierarchy to your design will not let your readers get intimidated by all the noise and clutter of the data.
Check out this handy infographic from DesignMantic that outlines the 15 golden principles of visual hierarchy that will benefit both your logo and web designs.