A friendly greeting and alternative to Hello/Hi
Hey there! How's it going?
A "some what" friendly greeting usually expressed in online chats especially when the intent in not exactly 100% genuine. Usually used by people when they want to make there presence known without getting to personal.
Oh look, Mary's friend Mike is online right now, and he is very influential. I might actually get something out of him later down the line so I should at least give him a greeting but I better not call him by name because I dont want to be his friend or anything. So I better just say "Hey There"