I work at a B&M and I see people buy and smoke on the spot and rarely are there problems.
I also see people walk in with their own sticks and buy a coke and stay to smoke. My feeling is since sooooooooooo few people do that, I suport the freedom to enjoy a cigar and I work at a place that allows that.
So, all in all, I'm for smoking cigars whenever and whereever one can!