Aurgh! This eats me up! "Lol" used to mean "laughing out loud." Today it is a punctuation mark.
Allow me to explain. An exclamation mark doesn't tell the readers anything new. It just tells them how the writer feels about what he or she wrote. For example:
"I'm going home" tells us where the author is going. "I'm going home!" tells us the exact same fact, but also tells us that the author is excited about this trip.
"Your mother-in-law called you an ugly bitch" tells us what your mother-in-law said about you. "Your mother-in-law called you an ugly bitch?" tells us the same fact and also tells us that the author is feeling surprised and incredulous.
Now we turn our attention to the new punctuation mark: "lol."
Below is an actual Facebook conversation:
Friend's status: everytime (sic.) I go to a cemetery I think "those lucky sons of bitches!"
Sympathetic friend comments: One day (unfortunately) you and I will be there as well. In the meantime try to enjoy your luck that you are of the "lucky" carbon to be alive. Afterwards you'll have eternity to be those "lucky sons of bitches."
*sigh* if only I can heed my own advice and preachings lol.
Suicidal-sounding status updater: I am enjoying it. Very much. Don't you see? lol
Please. Neither of these people was laughing out loud. "Lol," like the exclamation and question marks, tells us how the author feels about what he or she is writing. "Lol" means "Don't take what I'm writing too seriously. I don't really mean it. I don't know what I mean, so let's just pretend that I'm joking. After all jokes don't need to make sense lol"