Certifications are useful in getting your resume above those with the same amount of experience as yourself. However the most useful thing to have is professional experience. If you are going for a position and you have a certification, and there is another candidate which they like just as much as you, with the same amount of experience, but you have a certification and they do not, then that might be the bump that you need to get in the door.
However most certifications are designed to show experience using the product or technology at a specific level. A certification with no professional experience may not help much or at all.