Definition
Said when handing something over to someone or doing a favour to them, usually to draw the recipient's attention to the exchange; equivalent to “thank you” when receiving something.
Used to express disdain for someone's actions despite the speaker's hopes or expectations.
How People Actually Use It
1.A way of calling someone a hypocrite especially after receiving criticism. 2. Complimenting someone who has overcome adversity in their life
"1. Guest: I don't know why you keep inviting me to these parties. The drinks are warm the food is bland and the people are all the same Host: Yet here you are 2. Wow, when you asked me to invest in your restaurant, I never thought you would be so successful. Yet here you are"
Source: Urban Dictionary