Search Engine Roundtable is reporting on an email sent to select AdSense users last night asking them to participate in a "Custom Placement Pack" advertising program.

According to the email, republished by SERoundtable, Google is hand-selecting prominent sites to feature in "packs" to advertisers.  There aren't a lot of details about the program included in the email, but I'd guess Google wants to bundle groups of related sites for advertisers to bid on.  If you want to advertise on automobile sites, Google wants to be able to say "here… bid on this bundle of 30 of our best automotive websites".

To participate in the program, though, websites must place the medium rectangle ad unit on their site.  Google says in the email that this is the size most-requested by advertisers.  In addition, the ad must be placed above the fold so that visitors see it without having to scroll.  I think this is a first step in a future ramp-up of video ads.  Google wants their best publishers to have the infrastructure in place now so that a roll-out of video ads will be much quicker.

Reactions to the email are mixed.  It appears that hundreds (maybe thousands) of site owners received the email.  And most are wondering the same thing:  what do I get out of the deal?  Google wants people to place large ads above the folds of their sites without so much as a mention of the benefit to them.  If someone has an existing AdSense arrangement that's working (and I think we can assume that they are working if Google wants to feature these sites) why would they want to change things up and put potentially larger advertisements in prime content real estate just to help out advertisers?

In a related post, the Inside AdSense blog is publicising the newly-added ability for all AdSense users to create ad placements for their websites.  In a nutshell, ad placements are descriptive elements that tell advertisers the size, location, and surrounding content of your ad units.  In theory, by providing this information publishers can influence advertisers to bid on ad space on their sites.

Google says the bidding system already in place for AdSense will remain the same.  The AdSense system will still select the ad determined to make the most money for display.  By targeting specific ad placements, advertisers can make sure their ads are considered in the auction.  Google's computers will pull together advertisers bidding on your site's content and ad placement, run an auction from the entire lot, and select the best ad for display.

Look at all of this together.  Google is pushing banner and video ads.  Google is enhancing its existing search advertising platform.  It looks like Google is going after Madison Avenue (the major advertising agencies).  Until now, this has been Yahoo's territory.  Let the games/wars begin!