Best Way to Clean A bulletin board?

I work in a small office where we have a large bulletin board in the main waiting area. Ive only been there 2 years, and its been there for 10 years...The board is being used for people to post fliers and business cards. Its been filled up since I got there, and I want to clean it by throwing away some of them to allow room for more cards!..how does one go about doing that, aside from calling each card to see if they are still in business?