Updating is critical for tbases and more importantly updating your profile is beyond helpful to you in being found more often and more easily.
It's helps to keep tbases a free service for freelancers.
Every time you update you move to the top of search results lists where you match the search criteria used, it is more than helpful to you.
Try to UPDATE every time a contract or piece of work ends or once a month. It takes 5 mins or less!