my opinion only: you have 4 elevator companies. Really there are several when you add in fujitech, mitsubishi, etc...but there are 4 real big ones: Otis, Kone, Schindler, TK.
Think about this: Nike has to brand itself a popularize itself because the shoe market is extremely competitve, i can name 15 brands off the top of my head that compete with NIKE. Shoes are a commodity- you can buy a pair shoes that will protect your feet for 10 dollars or you can buy NIKE shoes for 80 dollars as a fashion statement or to look cool, NIKE has to brand itself because it is a commodity.
Elevators are not a commodity, they are a necessity. If people build buildings they must have elevators. Elevator companies market to Architects. Architects design the building. If elevator company A can get its product specificed in the building then chances are good that it will be able to install its product in the building.
Since each company basically has a 25% chance of getting the elevator installation, there is no need to mass market the product. They do outside sales to convince as many architects and building owners that their elevator is the best; the rest is a numbers and timing game.
Again- just my opinion