gmb21 - 3:16 pm on Jan 23, 2012 (gmt 0)

The landing page quality guidelines for AdWords MAY give some insight into how this will work. They state that, in a 1024 x 768 maximised window:

1. At least 30% of the above-the-fold area must be actual content. Content excludes headers, navigation, search boxes, etc.

2. Ad area above-the-fold must be less than or equal to actual content.

See the details in the 5th post on the following page:
[google.com...]