Using a product is not an absolute requirement for forming an informed opinion on it. There is enough literature and information out there that one can casually gather an insight into how Facebook works, what their policies are, and empirical observations about how it is used/experienced by others around oneself.

It is important to note however, that all that data gives you a very limited view of it.

I like to think I know a fair bit about cars/motor racing, but I'm positive that the few times I've spoken to actual professionals I come off as a bit of a fanboy who only knows one side of it. I can know all the physiological effects of drug abuse, but I can't know what it is like to be a drug addict without being one... etc.

I'm in the same situation re not having an account.

I work in web development and have had to integrate those disgusting 'like' buttons and examine closely the API for other jobs. All this led me to decide that Facebook is not for me.

I am very familiar with the site.. I just choose not to have an account. 98% of the people I know have accounts, and interestingly there is a group of people I know that are of the same mind as myself; have never had an account - and wont have an account. Additionally - they are all techies.

So, I follow everything that FB does - I just wont create an account.