Oh Shit Not You Again Doormat
A "Welcome!" mat just seems so ... old and trite and, in fact a little bullshit. We don't welcome everyone we see to our house, sometimes quite the opposite. This should keep some of the riff-raff and solicitors away.
The good people will see this mat, smile and maybe chuckle, and be glad that they have such cool, funny and smart friends for buying such a witty door mat!