Wow, I was wondering about that just yesterday. It seems to be common among realtors and mortgage company underlings - people that I don't normally have to deal with, but that are likely to use emoticons to end every paragraph.
When my teenage kids text me, I make sure that they use complete sentences. I'm a bit of a bastard that way, but hopefully they'll be better off later on in life.
http://static2.businessinsider.com/image/53358dd4ecad04e75a8...