On the surface this is taking a page out of client iFByPhone's playbook, a company out of the Netherlands has created PushCall. With their latest offering, PushCall makes it passible to click on a banner ad and make a call.
What makes so much of this possible is the same kind of Adobe Flash audio that is powering things like TringMe and now GizmoCall.
The difference between services like iFByPhone and Pushcall is what is going on behind the scenes. Web based companies want more than just click and connect. That's the difference between a neat idea, and a real business model.