As a professional, how do I get rated?

It is up to the Professional to make sure the Business does in fact leave a rating for you and the work you delivered.  It is voluntary system, much the same as the rating system  at ebay.  It is therefore in the best interest of the Professional that they to do the best job they can for their clients.  If a Business has not given you a rating, you should contact them and request that they do so.