Worth reading this article by Ryan Block, founder of gdgt.com, on why he quit Facebook and Instagram. I’m still on both, but largely inactive. The fact that a large number of family members and some good friends are on Facebook still keeps me there, but I’m fairly certain a day will come when that will cease to be a pull factor. He notes that it is specifically Facebook that is the problem:
Perhaps worst of all, in an era where we meticulously prune our online personae, services like Facebook require constant diligence and maintenance. On Twitter accounts, About.me profiles, or LinkedIn bios, at the very least users are empowered by complete control in their outward appearance. This is in contrast to Facebook and any other social tool that allows any user in its social graph to associate you with all manner of unrelated career- (or even potentially life-) changing posts or images.
Also:
We’d all be much better off simplifying our technological footprints and consolidating our trust in the few services that provide us the greatest value with the fewest unintended side effects.
One Size Fits One 