ComicBook.com previously reported that Pokemon Go appears to have new unused coding related to trading Pokemon. A recent examination of the game's code has also revealed some tantalizing clues about possible types of incense. A Redditor from /r/TheSilphRoad discovered three code items called "Item_incense_floral", "item_incense_spicy", and "item_incense_cool", which apparently weren't in previous versions of the game's code.
Currently, incense is used by players to attract Pokemon. Although fans discovered that incense works best when players are walking/running, there's been no confirmed way to control what sort of Pokemon appear because of incense. Those code items could be related to a new type of incense that attracts specific types of Pokemon. The "Spicy Incense" appears to line up with Fire Pokemon, while "Floral" and "Cool" Incense seem to match up with Grass and Water Types. Perhaps these incenses are ways for fans to attract more Bulbasaur, Charmanders and Squirtle?
It's also possible that the new incense types are just placeholders for other items not yet introduced in the game. Currently, Pokemon Go has several different types of berries embedded in the code which have yet to appear in the game. The Master Ball, a Poke Ball with a 100% capture rate, is also in Pokemon Go's coding.
Currently, there's only two ways to get incense: by hitting a milestone level (which occurs every 5 levels) or buy purchasing them from the store. Adding type-specific incense would be a possible way to "attract" additional players into making more in-game purchases. Many players were concerned that Pokemon Go would have micro-transaction exclusive items when the game was first announced as "free to play", but those fears have (so far) been largely unfounded.
So far, Niantic has been slow to roll out new features to Pokemon Go as they instead have worked on stabilizing the game's often crashing servers, fixing the game's broken tracking system, and attacked rampant cheating and third party app use. However, the most update introduced a new "Pokemon Appraisal" system that players can use to determine a Pokemon's secret "IV stats".