"Say you are in a strange city and need a hotel for the night. You pull out your phone, search for hotels on Google and see a nearby one listed at the top of the rankings, with a little phone icon that says, “Call.” You tap it, reach the hotel and ask for a room.
And just like that, Google made money. That icon was a so-called click-to-call ad, and the hotel paid Google for it when you called.
As more of us have access to the Internet and apps through our cellphones and tablets, advertisers are looking for new ways to reach us there..."
Via Brian Yanish - MarketingHits.com, Tami Cannizzaro, Digital SMBs