You can put it on your vcard. Basically it allows you to prove companies you can design software using specific tools.
But for us it was necessary because if a company wants to be a Microsoft Partner they have to be at least two people that have passed one of those tests. So they decided I had to do a test which is good for me, too.
If a company wants to be a Microsoft Partner it is a lot more expensive to get ALL their products (like complete development studio, all server, all OSes, ALL the documentation etc etc) if you don't have certifications.