Simply clapping is contagious, for example when there are a lot of us together and someone starts to clap then we all start to do it and get the feeling we need to be involved. I know as I was with my better half at a Michael Buble concert the other day and I was clapping. I could also feel the nervous tension around some of the men when their other halfs started to stand up, so when I stood up and saw a wave of other men stand up I assumed it must be contagious like clapping. I believe this must be a form of group behaviour where we like to be working together, united in our expression. This must therefore work for social media groups as well, where if you have a community of loyal engaged fans then start some hand clapping around your product and brand. Get everyone involved, make your audience feel supportive and happy to shout about you and your company. If everyone starts to work together you create a sense of goodwill and community where the priority is on value and sharing rather than an exchange of cash for goods.