They make money by driving people into their product and disrupting other companies. It's awesome really how disruptive Google is to competitors. They're making a larger argument for getting rid of a landline and even in time a voice plan... hell... if wi-fi is available you don't even need a data plan just a tablet or laptop with wifi. Voila - free phone calls and you're even more in love with Google. It's a very disruptive scenario they've sprung on the telcos today.
By increasing reliability and acquiring more behaviour from you - they know everything you do in another aspect of your life. It's easy with that info to target you with ads, or sell a connection with you to a company.
**prediction** - this will interface with Google streetview some day. You'll be able to simply 'walk' down a street and click on a house or company to call. There goes all phone book / yellow pages cos. Businesses will be buying the virtual real estate on Streetview.
GPS - Geolocation - you'll be able to simply ask your phone "Where is the closest (insert store here) and it'll dial that phone number for you.