The rules of engagement on

social media are different. I know that. I don't expect all the people I have "friended" or "followed" there  to be actual friends in real life - even when they have followed me back. 
I can remember an occasion on which someone else I know proudly announced that he was "friends" with someone quite well known on Facebook. Some months later he actually met them at an event and, of course, they had no idea who he was. He was devastated. Their "friend" list run to thousands.  
I cannot find the article - although I printed off a copy for the Senior Cat to read - but I recently read something about how many friends people need and how many they can handle on a face to face basis.
From memory it said everyone needs at least one friend and, as a minimum, it is preferable to have three or four. About the most  people can cope with is, again from memory, about 120. It is possible to know more people than that. I do. I suspect many people do but, for me, these people are acquaintances - not friends. My definition of friendship is something like "do I do more than just pass the time of day?" with them. Would I feel comfortable about phoning them? In other words, would they know who I was if I phoned them? Would I "have a cuppa", have an extended conversation, loan them something, go somewhere with them, give them more than a little casual help? Even then I know that there are degrees of friendship.
I was surprised recently when someone else suggested that the people in a group I belong to were "friends". Some of the people in the group are friends but I would consider most people "acquaintances" - people I am on social greeting terms with.
I know many social media "friendships" are really just such acquaintances. If the other person recognises your name they will be polite - and that's all you can expect. There will be a few, a treasured few, who have become more than that. When you eventually meet them they will be as pleased as you are at the physical meeting. Your perception of each other will have been pretty accurate and you will get along well together.   You might well "have a cuppa" - and you will both take it from there.
I have met several people I have come to know through social media. One has actually stayed with Middle Cat. Middle Cat's boys have stayed with her. I have met another for that "cuppa" more than once - and if she moves back to the city we may see one another more often. There's another one I felt instantly comfortable with - we sat in the shade on a very hot day and talked and talked! I have yet to meet some of the people who will read this - but I hope I will. They have expressed a desire to meet. That's good. We all know that the Senior Cat won't be here when it happens and I know they understand that. I hope I'll have the confidence to make the journey.
But there are still rules of engagement for other relationships. Even on social media it is not polite to walk out on the many people who have given you a great deal of support without, at very least, saying something like, "Social media has become too much for me to handle. It's too time consuming. Please don't take it personally but I am  'unfriending' a lot of you."
Now you will never what support they might have given you - because they aren't going to know what you might need.