I have never used it and I'm not a fan of its use. I often stop reading something if there are lots of lol's in it. I find it really distracting tbh. I also get annoyed when people say something not vaguely amusing (eg i'm making a cup of tea) then add "lol". Or say something cruel and think it's ok to add lol at the end.
There you go I've gone from never ever using it to 3 times in one post lol.