The template > slot > ad mental model is engrained both in advertisers, planners and web sites. Providing space for ads needs to be broadened into multiple spaces for one ad concept. This requires closer collaboration between advertisers and web sites, designers and marketeers and sales teams.
This is exactly the issue I’ve faced in my redesign work for STV. My solution, and one that seems to been accepted, has been to:
min-widthon ad containers
With STV’s permission, I’d love to publish some of our solutions.