YES! I also think it’s a pity that most users categorically reject ad cards. I’ve sent over 2.000 cards so far and I didn’t solve the mystery “Why?” neither… 
This is my collection 
I’d like to recommend this topic for further information, it’s about ad cards as well.
This month, some big main stations in Germany distribute great ad cards drawn by an artist, showing 27 cities with funny, witty illustrations.
Nuremberg:
Munich:
I asked myself several times if I could send them to a member rejecting ad cards…