As many publishers already know, mobile click to call is a big driver of pay per call and it's a big reason why pay per call is currently growing.
However, don't forget that other forms of advertising are also great for pay per call marketing.
For media channels like display, print, radio, TV, desktop, email, ppv, etc. we can still get these users to pick up the phone and make a call. You just need to create a "CALL" to action!
Here's a few examples of how you can get users to physically pick up their phone and start dialing:
"Call Now for an Immediate Quote"
"Phone Only Deals Available"
"Save by Calling Today"
"Simple Over the Phone Approval"
"No Hassle Over the Phone Consultation"
"Don't Wait. Get Answers by Calling Now!"
A lot of the same principles that we already know apply, create urgency, sell the user, give them an action to take, etc.
Click to call is NOT the only way to deliver calls to campaigns. With a little creativity and messaging you can get the phone to ring!
PS: Another tip for driving calls over form fills is to create a long, difficult to complete, detailed form. Then give an "easy" option, like "call now"! 
PPV is definitely a good option for this! Thanks for the share man sick tips!
Nice tips!
Have any stats on PPC traffic how much comes from mobile traffic?
@ringpartner: I still don't get how ppv works with ppcall. Is it just a matter of the click to call feature being set up on the pops? Thanks.
Ok. I got it. Physically dialling the number on the pop instead of clicking. Thanks @ringpartner.