Social networking sites pervade the World Wide Web and have millions of users worldwide. This provides ample opportunity for brands and organisations to reach out to a large and diverse audience. They do so by creating content and spreading it across the social network. Most popular social networks follow a timeline based homepage to display such content to the end users. Content once posted on the timeline, remains visible for a limited time, determined by the rate of content generation in the network. There are various ways by which brands can become more visible on the timeline of their followers, for instance by retransmitting/advertising their content from time to time. Hence, with multiple content creators in the network, there is a competition over a user's timeline, which we analyse in this paper. We first characterise the occupancy distribution of a given user's timeline and then use queueing techniques to analyse the period of time a content is present on a given timeline. We then study the competition between different content creators and characterise the equilibrium rate of content generation. We finally provide some numerical results, which provide insights into the effect of various system parameters.