First of all every profile states the purpose of what people are looking for (communication, relationship, etc).

And if a person doesn't have a full profile, then you can ask what you want to know. That is exactly the whole idea of my post.

But suit yourself! Write your "hi" and "hello" and "what are you doing here?" phrases. As for me: they go straight into the bin, unresponded. Even talking about the weather is more exciting than that.