First and the most important: build something that customers really need, not what you think they might want and build something to make their life easier. Basically, find a need and fill it.
Second, start something that you are passionate about. Don’t start something just because its trendy or everyone else is doing.
Third, great branding and marketing is critical for a consumer site. How to use viral marketing promotion techniques to penetrate targeted demographics is the key to success for consumer/social network sites.
