[sunshine]

The biggest AdSense secret is that there aren't any. It's very simple and common sense. However people tend to ignore the obvious. For exmaple, there is a popular myth that "ugly sites pay better". Folks usually give examples of DogBreedInfo.Com ($650 a day) or PlentyOfFish.Com ($10000 a day). We know how much they make, because Google provided this information on the official blog.

It's pretty clear (to me) that the major success factor is the "clickability factor" and it's not the same as "good matching".

Now, if you create a site about dogs and people go there to find out about dog training, chances are, people will click ads about dog training. Or dog breeding. And if you have a dating site where singles look for a date, it makes perfect sense that they click dating ads.
However, if you have a "TV site" or a "Game site" or a "Music site", the money simply isn't there. Not because Google is bad at matching - quite the contrary, but "clickability" isn't there.

Something to keep in mind when you start your next site.