It would be nice if you could do this to get the impressions, but you don't need this to track clicks if the links are coming to your website and/or Marketo landing pages. Just add one or more querystring parameters to the ad with unique value(s) for things you want to track (e.g. campaign, content, ad size, etc.). You can use the Google utm parameters. When the visitor hits your page, you can have a triggered smart campaign add them to a static list, update their Lead Source field value, etc. The only thing you can't do is add anonymous visitors to a banner ad program Program, but once they become known they can be added after the fact if you want.