This article focuses on click to call using a PC, but the advantages for mobile will be easier to see. You are clicking on an icon which is a hyperlink. Instead being directed to a website, you're directed to a phone number. The mouse is dialer.
From NY Times Pick up the phone, your search term is calling
GOOGLE is going 20th century.
The company, whose empire is based on its ability to connect people and businesses through computers, is now connecting them the old-fashioned way — over the phone.
Just as in pay-per-click advertising, pay-per-call marketers bid for the right to have their ads appear near the top results of search queries, and pay only when someone actually uses them. Consumers either choose the click-to-call option or simply dial the number in the ad.
In either case, the number is a dedicated line that middleman companies like Ingenio or eStara, a company based in Reston, Va., have procured for each advertiser. Those companies connect and log the call, charge the advertisers and share the money with the site on which the ad appeared.
There's the problem, the middleman. There is a way to eliminate the middleman and get a direct connection.