According to Android Police, there were strings of code hidden inside the Android 4.4 KitKat Dialer that involved advertisements. The strings in question have to do with ads being enabled and disabled. Being that it is in the Dialer app, it would mean that as you search for a contact such as a business, you would get relevant ads. Another set a strings included Google’s AdMob advertising network. But don’t worry because a reader was quick to point out that this kind of stuff has been appearing in Dialer / Phone apps in the past.
Ars Technica’s Ron Amadeo was able to get in touch with Google and the company assured him that advertisements are not coming to the Dialer app. The strings were merely old and left behind. So breathe easy move along with your day, folks.