Facebook is now officially the largest website in the world (in terms of visitors), and has an estimated 500 million users worldwide - the average number of friends is 130. Around one third of the US population is now on facebook, so when you look at the estimated $1 billion revenue that will be generated next year, it seems quite a low number - an average of about $2 per user. In contrast, Google has about that same number of annual unique visitors, and generated $6.8 billion in just the second quarter of 2010 (which is about 24 times more than facebook) - that's about $48 per user. Twitter has about $10 per user based on recent projections.

So the dilemma faced by Facebook now is how to convert visitors into money. If it can emulate google's success in generating income from visitors, then it could be looking at a massive increase in revenue, however the problem is that people like facebook because it's free, and relatively light on advertising. Once you start throwing marketing messages in people's faces, they quickly turn off and what was once the biggest social networking site in the world, might start showing a steep decline in usage.

There are also privacy and trust aspects to facebook that are concerning some groups, which is not going away, and my prediction is that before long, there will be a court case in the European court concerning right to privacy before the end of next year.