In The Netherlands, Marktplaats (an eBay company) is testing a "click-and-get-called" banner. Basically, when you click on a special banner, a pop-up opens asking you to fill in your telephone number in order to get called by the advertiser. As De Koopman blog (in Dutch) explains, the advertiser is charged on a CPM and a lead base.
To see the banner in action, click here and visit the Marktplaats jobs section.
Although I keep in mind this click&call; is in a testing phase, I have a few remarks.
1. The quality/attractiveness of the banner used is pretty low (see picture above) and might experience problems in generating any kind of click.
2. Only if you click on the bottom part of the banner you are taken to the call page. If you click on the top part, you're just taken to the advertiser's homepage.
3. Visitors can be called anywhere in the world (I filled in my Italian phone number). This is good if you run a global campaign, but definitely a waste of money for the site advertised in the experiment (a Dutch professional education provider).