I stumbled across this type of adsense ad. I think it is a permalink ad? But nevertheless I do not have these type of ads in my Adsense Account?
I don't know the details, but I know that if you have a ridiculous amount of traffic, you have different options for ad designs. We're talking like millions of page views a month I think.
It is totally unknown format of advertisement! i checked again & again but unable to find any of this kind... I think it may be available for Google's Premium Publishers
i have seen these type of ads on those sites which have millions of impressions per day and defienetly there are premium members and in most of the site who have these type of ads when u will click on their ad it will open in a separate window rather than same window,
Its pretty normal the site must be having premium adsense account which allows to modify it looks and match that of site - its everywhere in internet - just see some of the famous sites you will come to know... Hope this helps...
See example at ezinearticles. There are a lot of ads with non standard formats. Seem it's allowed only for premium site which has high traffic.
These are Premium Publishers my friend. They even can place more ad blocks than non-premium members who only can place 3 ad blocks. Also Premium Publishers get $5 CPM.
If you generate good money for adsense groups then you will be indexed in premium publishers . Then you can also get some special services like them , which will help you to generate more revenue for them and you too .