Click-to-call is a way for advertisers to increase conversion rates by allowing a link with a phone number in the ad. When the user clicks the link from within a mobile browser the device calls that number.
Most modern browsers support this, but make sure the target mobile device support this before using this in a campaign. You can try it from a mobile device using the below link. How the device handles these links is entirely up to the device manufacturer, and so will vary between devices.
Visit this page from a mobile browser and try for yourself. Click here to call
Link to a phone number using a tel: link. A tel: link is like an http: link, but it will call a phone number instead of open a web page when you click it.
In an HTML creative, use an <a> tag with a tel: link like this:
<a href="tel:+46-1234-4567">Click here to call</a>
With an image or flash creative, enter a click url with a tel: link like this
tel:+46-1234-4567
http:
or // in a tel: link. This will break the link.You can use Apple's iTunes Link Maker to create an http: link to a specific item in the iTunes store and use it as a click url. On supported devices, clicking a creative with an iTunes click url will open the iTunes, iBook, or App Store app and go to the linked item. On other devices, it will open the iTunes web page for the item.