/Shrug, different companies have different marketing philosophies. Advertising can be very expensive and ineffective for its price. That's why certain companies go light on advertising and channel more of the budget into the actual products itself. Sometimes its best to just make great products and let the reviews/word-of-mouth do the selling itself.
Plus there's multiple ways to get more bang for your buck in promotion that doesn't involve the most expensive form of advertising: TV ads.
A lot of people are under the assumption that throwing money into tv ads, will always automatically be a good decision, but thats rarely the truth.