I'm not on Pinterest either and, largely because of their policy regarding any photos you should post there. Basically, Pinterest assumes the copyright of any photos or artwork or any creative material that people post. If you do get a Pinterest account be sure to read all the details about who owns whatever material or photos are posted. Lots of people don't bother to read all the tiny details of a site's policy regarding the posting of various things and, in the case of Pineterest, can find out the hard way when Pinterest reposts those photos, artwork, ect. without the original copyright holder's permission. If you don't care what happens to your creative stuff, then, go ahead and get an account. Me? No way!
Mary C.