Medco has a smart one. And its positioning is ever smarter.
OK, let's start with this: Using colloquial Arabic does not always work (Halabi is a case in point here). Medco via - mostly - its petrol stations is acing it. Espacially that it is using it in the way we write it in a Latinized language (certain letters in Arabic appear very close to other signifiers in Latin - and this goes back when people were using MSN Messenger and Yahoo! Messenger or ICQ - what? - did not have Arabic support so people invented the language as they went along).
The Medco line translates into "we can never have enough of you - don't be strangers". Which is obviously a way to entice people to come back to the Lebanon. Which, honestly, is a nice way of saying it in Arabic - slang Arabic. Now, the interesting bit?
This is placed right at the entrance of the airport. Which honestly is very neat.
Because you are telling people to come back right at the place where they are the most emotionally vulnerable.
As I said, Medco played it smart.