Using codes as ADs?

Was wondering if it’s worth putting in-game codes as ads or not. Since I’ve seen quite a handful of them lately. Here’s mines. I also need opinions on design-wise.
RECAD1


It makes it unfair to mobile players who don’t see the ads. Maybe it will help? It just takes so much space on the ad it doesn’t seem worth it.

We don’t talk about the forbidden box ad.

Tried going unique with set amount of fonts for each letter.