An effective online presence can help ensure your professional credentials are available for recruiters to see. Professional networking sites allow you to set out your skills and experience in a logical manner, like a good resume, while other platforms enable you to develop and broadcast your views and opinions. With one in four people around the world using social networking, according to industry research firm eMarketer, these sites have the potential to hook you up with thousands of like-minded individuals and recruiters, ensuring visibility in the jobs market.