gosh.. this is funny and no one commented? Oh, or are the comments eaten up by the one-month comment monster? Anyway! I <3 this one! And yes, it is bad karma to rub it on the welcome mat... but think about it.
It is an even more bad karma if you don't and step inside with dog poo (say) and soil the marble floor (again say) of whosoever lives there.. and probably the worst karma is to let them clean it up...!