I use Facebook with my Fanpage and my Profile. Facebook is a good way for me to engage and entertain my customers/fans. I rarely use facebook to pitch it's more for branding myself as an authority with my messages.
I use Twitter and Pinterest because they are busy, lots of traffic, some of which view my blog posts. You get to meet some people and do some networking, too. Also, I find them fun at times, though I am not a daily user anymore - too much to do.
Personally I am using Facebook. But professionally I have use following websites: Facebook, Twitter, Pinterest, Google+, LinkedIn
After updates in Google search algorithms , I consider Google+ most important. It has been given priority in searches
I'm a writer, and LinkedIn cators to journalists. They even have a setup where you can get free premium for a year if you participate in a special training. It's also far more professional than FB most of the time.
Google plus is good because all your circles see your website in google search f they join your business circle. And if for just personal, they will be emailed your post. Facebook great ability to reach deeply in to network reaching friends, and their friends as well LinkedIn great news feed and targeted customers. Slow to build but a well developed profile can do a lot
Personally I use: - Facebook for communicate detailed informations to "fans" - Twitter for micro (really micro, I mean daily smallest posting) blogging - Google + to gain trust (trying to achieve trust) In my opinion, to use those properties at their best, automation is becoming a must. I am gonna exploring that direction soon.
All the brands you see sharing posts are usually always automated. Nothing wrong with making it easier to post. Some people think Google would actually penalize people for that.
I use personal facebook to coach and motivate my audiences. I also reply on my high ranking keyword youtube videos and my blog comments.