I would say that indexing and making usable information in different contexts is their core competency (Search, Email, Maps, Desktop, Android, etc.) Advertising is a "tack on" to bring in the money, it's not where they are developing new value to the end user. Ad relevancy is really just a natural extension of their Search algorithm. If you're a business person you might say Ads is all Google is, but they still need to develop compelling products (core competency) to bring in views.