I'd be interested to keep seeing more stuff come out about how the actual mechanics of the game work, because I'm fairly certain that two different players don't find the same pokemon in the same places. Was sitting on my porch with some friends last night and used an incense to draw pokemon, caught 4-5, but the others around me didn't ever see anything.
In other news, I evolved a Pidgeotto into a PIdgeot today, and tried going to the gym on the corner of Lincoln Square in Chicago. I promptly realized that there are people who have not stopped playing this for a single second since it came out because I didn't stand a chance.
I wonder if the incense only applies to your account, but the wild pokemon are consistent for various areas.....