I was having a real business (I swear) conversation with a colleague recently, when the subject turned to another person (Person X) with which both myself and my colleague are very well acquainted. I mentioned that I had not heard from Person X in quite some time, and I wondered why this person had not taken time to contact me (the context, of which the specifics don't really matter), was that in my view this person really should have reached out to me on some things and he/she had not for a long time.
My colleague said something along the lines of 'Person X is really active on Facebook. Just post something on their wall if you want to get in touch with him/her.'
And I kind of cringed for two reasons I suppose. One, I don't really want to do 'business' on Facebook, and two, in truth I don't really want to do anything on Facebook. I have an account there sure, I am not a Luddite, but I don't check it all that often, I never post anything other than my blogs and the HR Happy Hour Shows that auto-post there, and for the most part I just ignore the site. I still am reasonably active on Twitter (mostly for professional reasons) and for personal/social kinds of things, I use Instagram. 
But that's just me. Most folks have their preferred ways of online social interaction, for both their business and for their personal reasons, and I don't suggest that anyone's approach is wrong or right or even that anyone should agree with me. But to this situation with me and Person X, who is (it seems) conducting a lot of business via Facebook, it looks like unless one of us moves to change our preferred methods of interaction, we will keep missing each other for the most part. I guess that is just how it is.
That's a long pre-amble to a shorter, more obvious point. We, or most of us surely, if we are actually busy with real work, family, friends, etc., simply can't be that active, present, and aware of all the things that are going on in our industries across the myriad of social platforms (and in-person events), all of the time. After some time of trying to keep aware and active of industry people and news and events and even opportunities on Twitter, Facebook, LinkedIn, Instagram, Google+, Pinterest, (and often using multiple personas or accounts), I think at least for me, that eventually you have to settle on the one or two that you either enjoy the most, or, get the most value from. For me, it is Twitter and Instagram. For others, like Person X, it seems to be Facebook.
And that small difference, that seemingly insignificant divergence in preferences, (and yes, I know that I could just CALL this Person X, but who does that any more?), actually does become pretty significant over time.
Back in the day, when you as a 12 year old kid moved away from your home town you basically lost all contact with your circle of friends and had to start all over from scratch in your new town and school. Even though you could have still stayed in touch with your old friends, you almost never did. It just was too burdensome to call or send letters or postcards when you could just walk outside and interact with your new friends instead.
That is kind of how I look at my old friends/associates over on Facebook now in a way. Sure, I could go over there and see what is going on, but it's just easier to not do that, and stay where I have become more comfortable. So I am missing out, I guess. So be it. That is what not being present on a platform can do to you in 2015.
Person X, give me a call sometime.