Successful adsense blogs
 

I have come across many blogs that are extremely succesful with adsense, by and large, most of them tend to be tech blogs. These blogs tend to review new gadgets and electronics. Does anyone have example of other blogs on different topics that do well. Are these people creating these blogs because its a topics they deeply knowldegable.

Many blogs on AdSense/ Internet Earning are also quite succesfull, for example problogger.