those business cards are kinda worthless. Most of the time they would go right in the trash. I would call and ask to speak to the manager/owner, and tell them that I will not be supporting their business. Doesn't matter anyway. Those signs don't mean squat. They have no legal weight. You are supposed to be carrying CONCEALED, so how would they know?
The right to stand your ground, or Castle Doctrine was signed into law last summer, took effect last fall. Basically it says that anywhere you are legally entitled to be, you do not have to retreat before using deadly force to stop an attack that causes you to fear for you life or other's lives, rape, or if you are being car jacked. If you are in your home, you used to have to try to get away... not anymore. Some POS breaks into your house, it is automatically presumed he is there with intent to commit great bodily harm, rape, or murder. About time we got some laws that made some sense. Although I did see a video interview on NRAnews.com where Texas folks were saying that they wouldn't use deadly force to protect themselves from a criminal.... "you shouldn't have the right to shoot someone...." even though they want to slit your throat
ETA: Those signs that say no guns, I look at them as though they apply to gang bangers. If you read the back of the CPL if says "this license allows the licensee to carry a pistol anywhere in the state...(list of pistol free zones)" it doesn't say except at Mom & Pops little store. So F em and let them get robbed by the gang bangers who now know they don't like guns.