Yes "conspicuously" is in the law. I'm not going to advise you to ignore the legally insufficient sign. If you do and you get a ticket that will have to be your defense. Remember though, an untested defense is almost as good as no defense at all, so the only ones that will get rich from your mistake is the criminal defense lawyer (not my specialty). However, since you know about the sign, conspicuous or not, you are on notice so, your defense just slipped a few more notches.
I know I've walked into a store where the sign wasn't posted well, and I saw it on a later visit. Almost walked into the bank today with my concealed weapon. Didn't feel safe going naked, and didn't want to be inconvenienced walking back to the truck, locking up my weapon, then going back to the bank unarmed, so I just got back into my truck and took care of business at the drive through and didn't care that the people behind me were inconvenienced because my transaction took a long time.
As our organization and the number of CCWs grows, we will become a force to be reckoned with, until then, keep handing out the cards and taking your business elsewhere.