Came across this site today and that square ad in the middle looks really well blended. It looks just like another part of the site! Not to mention the fact that the slightly different color made me notice it first before any sections of the page. Kudos to whoever you are
For some sites, blending will work best when totally blended ... but then it can be too hard to spot which are ads. In other cases, partial blending like this can be highly beneficial as it prevents ad blindness, appears to be part of the site, doesn't promote any bad methods and actively draws your attention to it.
The tutorialized site, surely has been blended well. But, was it necessary to have "ads by google" heading on top of each ad?