Exactly. When I was running WiFi for PyCon, I kept the radios lower (on tables) and the power levels at the lower end (especially for 2.4GHz, which a lot of devices still were limited to at the time). Human bodies do a good job of limiting the cell size and interference between adjacent APs in that model. I could count on at least a couple people every conference to track me down and tell me I needed to increase the power on the APs. ;-)