Adds realism? What? My first encounter with in game ads was in Planetside, on a far-from-Earth planet in the distant future. I had to rush back to base to re-arm.
Plastered all over this non-Earth future base were ads for Deuce Bigalow 2.
It felt so real! It wasn't jarringly out of place at all. On a side note, that was when I stopped playing Planetside.