BTW - By The Way
"By The Way" used as a short form "BTW" while chatting or writing on any social networking site like facebook. It's common now a days to use sentences in form of internet slang or in abbreviated form, like the one we are talking about.
In a Conversation:
Person2: Hi, Wass up
Person1: Nothing, Just chillin, wat about you ?
Person2: Planning to go to the beach.
Person1: Ok. BTW! Did you read my book ?
Person2: No. not yet, i will read it tommorow.