Personally, I think the practice of adding "lol" to everything is more snarky than
is.
Example:
Your mama smells so much like rotten tuna that the stray cats in the neighborhood follow her home from work. lol.
By adding the "lol" at the end, the poster is in effect saying, "Damn right your mama stinks, but by adding lol at the end I've turned it into a lighthearted, harmless statement and if you call me out on it I'll play innocent, say I was only joking and tell you that you lack a sense of humor