Good CTR, any case study?

Hi, I know that it's difficult to say which CTR is a good and satisfying one as it depends on various factors, so maybe someone could present case studies showing why a particular CTR was good. Thanks

 

Pretty obvious that CTR depends on ad's quality. Like if you see some awful image, you won't click on it. And of course don't forget about proper targeting. Here's a good read, check it out: http://www.wordstream.com/blog/ws/2011/11/09/target-the-right-person

 

Thanks for your help and the example. I'm looking for such practical explanations