Using street art as an advertisement or promotional material is becoming more and more popular these days. Here we have an especially good example of how this can be done right, in my opinion. Artist Retna was commissioned by Louis Vuitton to paint their building, so this is what he came up with. For those of you who don't know Retna, don't worry if you can't read what he has written. No one really can, but it's sort of his thing. He made up his own calligraphy / language and has been doing it for a long time.