Personally, Facebook has helped me to reconnect with friends from my high school and college. Some of them may share the same interest or in the same industry as myself but all these were undiscovered back then.
Professionally, since I'm in the realm of Internet marketing, I guess something that is interesting and worth nothing is that Facebook seems to have established itself ahead of Google in the heads of my clients (small business owners). Every new client that I managed to sign up will tell me something like, hey, what about Facebook?
As far as content is concern, I've also started taking cues from the number of likes and comments to determine what I share on Facebook Pages as well as what I publish on my blog.
Without a doubt, Facebook has definitely changed my life in a huge way.