"Keep Smiling"...Why?

Why is it, that nearly every new message I get from some random guy from the internet, signs their messages with the phrase "keep smiling"? Is that the new thing now? Is it suppose to leave me smiling to myself and thinking about him? Or thinking 'awww, he's so sweet', he must like my smile? Are all these guys who've written me, friends of some sort and one has basically copied off the next when writing strange women online for lack of creativity? Am I suppose to feel enlightened by his percieved positivity? Am I suppose to automatically smile after reading it?

First, am I smiling to begin with? Do I look like the type of person that likes to walk around cheesing all day? Do I need to smile, cause personally, I'm happy with my usual demeanor. Can't I just be? Oh, that's right. I can.

"Keep smiling?" Who cares??? Course it never bothers me when they sign it 'stay beautiful', cause well...that actually makes sense.