To quickly answer the questions you posed: It's up to you if it's worth the effort, but for me it would not be. The entire value of a social network is who you can connect to. I actually have made new friends online using Facebook (as well as other social services, but Facebook would be the most 'fruitful').

I am a fairly avid user of Facebook. I upload photos very regularly. I check in at locations. I tag people and am tagged by people. Nearly all events I organize and/or attend are through Facebook. After text messages Facebook is my primary method of direct communication and it is my main method of passive/broadcast communication.

To say it's a highly integrated part of my life is an understatement. It's both the primary hub of my social life as well as my life journal. The life journal aspect has been so useful to me that I will occasionally post entries visible only to myself. Why keep a separate journal elsewhere, when I can just augment a timeline of nearly everything I am doing?

About a year and a half ago I started to get interested in EDM (electronic dance music.) Finding out about all the local events was difficult at first. I also quickly recognized that the local EDM scene was fairly small and status driven. Being socially connected (high status) had a lot of utility value. So I tackled both problems by starting a new Facebook group dedicated to promoting local EDM events and artists. At first I tried making connections the old fashioned way of meeting people at events/clubs; even going so far as to make little business cards for my group. Quickly I realized I could 'friend spider' my way into a populous group. I would just friend request with people in the scene and add them to the group, always with a polite message... better to ask forgiveness than permission. Quickly the 'people you may know' sped up this process. If it said I had 100+ mutual friends I knew it was someone who would accept my request and was involved in the scene.

In the end I have over a thousand 'friends', of which I have met perhaps 200 and would consider perhaps 50 real friends. But my scheme worked. I now know everything going on and gained enough status to accomplish some things that would have been impossible otherwise. On reflection I wish I had done all this with a secondary profile and left my primary profile to only connect with people I am close with, but the signal-to-noise ratio is surprisingly easy to manage when you don't mind hiding posts.

After all that you might think I am a fan of Facebook. I'm not. I don't trust them and I don't like how reliant I am on them. If my profile were deleted it would have a big impact. I know I am the product being sold to the real customers (advertisers) and privacy is a secondary concern. I would love to switch to a secure decentralized social network such as what Diaspora promised. Something which allows me control my own data.

But that won't happen. Facebook is here to stay and thus I will continue to be a part of the machine. The reason is pretty simple. Facebook has the social graph. Moving a social graph of Facebook's size is an event I think impossible without something drastic happening. The value in a social network is the social graph.

I didn't buy an FB stock yet, but that's because I don't have any spare money to gamble with at the moment. If I did and I was looking for a good long term investment I would feel pretty comfortable dumping it in FB. Anyone who thinks a company that knows that much information about that many people is not going to be able to turn that into a huge profit center strikes me as short sighted. I'm not talking about them selling data to other companies either... Eventually I think Facebook will know what you want to buy before you do. Google has good reason to be afraid.