[header] How to market your social networking site and earn money from it [title] Choose a specific category or market. [step] Decide which niche you can cater to. It can be focused on particular group or category like college students of a community, single parents, baby boomers, and the like. 
You can save money by focusing on a single niche instead of wanting to get everyone to join. Potential subscribers will always have the inclination to join in networks of people with like interests and background.