If you're like me you might've been out there trying to catch 'em all, stressed out about making the most outta your limited supply of incense, and completely unaware that the best way to attract Pokémon while using an incense is to jog...at exactly 7.5 miles per hour. So, reasonably damn fast.
Yes, according to Pokémon GO's coding (first discovered by the Redditor __isitin__), Incense'll spawn one Pokémon every five minutes, if the player is not moving around. Except, the spawn rate surges to once a minute if a player travels at least 200 meters between spawns---about 7.5 MPH.
Based off Pokémon GO's frustratingly glitchy tracking system, and players actually taking pit stops to catch the Pokémon they find---you'd probably be able to catch between 10-15 Pokémon while your incense is active.