just a shot version of smile :-)

ahaha It's something like smile. First it was ":))" and then only ")"

Masoud, Soozical, it's just either 1) more lazy or 2) smiling lightly, where the joke/situation doesn't deserves accentuated smile. The thing is... Well, 'lol' - is 3 letters. Letters!! While ')' is just a punctuation mark. Using ) extensively one can't make ones text unreadable and ugly, as it would, if it was flooded with lol-s. So the 'смайлик' slowly evolves into a punctuation mark of the mood and intionation). Some people 1. never use it, some use it 2. after nearly every phrase, some use it 3. to mark a joke, so.... we have 4. peoples (usually girls) who feel that you are angry/sound angry if you don't use ')' enough; and 5. peoples, who may say something rude)/impolite/incorrect/nonsense/stupid (or something that may be misinterpreted as such) - and then ask "It was a joke, obviously. Why haven't you noticed the smiley????".

You've pointed out something that has been a question for me for a while. At first I thought they unintentionally miss the extra ":" but then I noted that almost all of Russians do the same. One funny reason might be that they think their smile is much more beautiful that "eyes + smile"!