Why can't google let us place our ads without having their damn tags all over them. It's super annoying to have "Ads by google" on three Ad blocks of a website. Also since every site is using adsense lately I think the users are getting less likely to click the ads.
There are so many sponsered advertiser so google want people to know that its their ads which are displayed there
I guess it goes both ways. I just find that having three "Ads by google" logos close to each other looks kinda poopy
Google add them to notice visitor that "this is banner". If you don't want the google to display it, you must register to premier account. That mean you must at less 20 million impression per month.
bored, this can be across a few sites. Ads by google tag is there for almost all ads but certain image ads dont have it. Its one of the way for google to tell the world that its a google ad. Secondly people can click on Ads by google might prolly signup. That gets them new customer (no one thought about this?)
I've read it somewhere that Google wants it there so as not to confuse users between your contents and their own ads. Yea probably CTR will increase if the words aren't there.