Perhaps Google is beginning to get a bit of class as it gets bigger. Why would they need to plaster 'Ads by Google' or even worse 'Ads by Gooooogle' every time they place an ad for you. It's almost like a web designer insisting that there should be a link to the web designer's website on every web page they produce for clients. Of course if it's only a text link, then it's important that the viewer can spot it's an ad. However an image ad is clearly an ad.