Over at V7N there is a question about google emailing custom adsense sizing to you.

Specifically,

“Custom placement packs are selections of individually-reviewed sites designed for our largest brand advertisers. We would like to feature your site more frequently in these advertiser packages, but to do so, we need you to place more image and text-enabled medium rectangle ad units (300×250) on your site. Visit https://www.google.com/adsense/adformats to see a sample of the medium rectangle unit. The medium rectangle is the most demanded size among our brand advertisers that utilize these packages for both text and image ads. These advertisers want to ensure they reach visitors on high quality sites like yours, and are willing to bid more for ads prominently displayed on these sites. They require that the units be placed “above the fold” on a page so that the ads are immediately visible to your site’s visitors without scrolling down”.

I haven’t seen anything on this .  Anyone else?