I've got an advertiser on my site with a phone number in their ad. Is that allowed? I won't block since most people would probably click for info first, but it's an obvious attempt to avoid paying for advertising, so..
Using a phone number may not be an attempt to circumvent paying for a click, but in the advertisers eyes they are "branding themselves" as also available by phone. As a publisher however, I often decline advertisers who place their phone number in their ad because more and more often consumers ARE picking up the phone instead of clicking, especially when its (phone or contact info) they were looking for.
You should not use that thing. It is some kind of differentiation between the several advertisers whose ads are served in your webpage. Advertisers may cause the problem.