According to Artaic's blog, "The codes don’t only have to be website links, text can also be embedded into the codes. The tile QR codes could provide interesting insights into their installation locations, telephone numbers, or humorous quips."
The idea of making permanent an entity that heretofore has been fairly ephemeral is interesting. QR codes show up a lot on soda cans, bus stop signs, and yogurt containers. Does (literally) plastering them onto buildings change how you perceive them? Would you whip out your smart phone at a cafe and start scanning a wall?