If you are looking for some profits from using pay per call strategy, you could rely on the most popular among the group, Google. Google AdWords usecallbox.com/ are capable of creating advertisements that are casts on Google search engine as well as other properties owned by Google.
Ad words are key to PPC in certain ways that each time a search is initiated; Google will dig into the pool of AdWords and comes up with winners among the lot to be displayed in the page. These winners are chosen based on their relevance, quality and the size of their keywords via a pre-set calculation.
The whole system resembles an auction scenario. How efficient your Pay Per Call Marketing technique is will be dependent on the keywords and types of match you choose. You are supposed to focus on the relevance of your keyword, quality of landing page and the score quality.