I presume you're trying to sell advertising space of rooftops near airports.
The ratio of window seats to non-window seats on aircraft types ranges from 1/4 for regional jets and turboprops, 2/5 or 1/3 for single aisle types and anywhere from 2/7 to 1/5 for widebody types.
Basically, only window seats have a "good" view of the ground.
Look at seatguru.com to get an idea of how many window seats to non window seats there are on various types. Remember to divide everything by 2 because only half the airplane can see a given object on the ground. Analyzing how many eyes per day might see a sign from the air is a tough job, but it should be possible.
Spell check is a false dog