The truth of the matter is that Google uses adsense approval bot to approval applications. They have grown to the extent that they cannot manually approve all application. The bot crawls your website to understand its content and other factors and then score it thereafter.
The bot look for keywords to determine if they have ads to serve,etc.
So you can have 30,000 post and you will still get a message “insufficient content”
There are some adsense approval services around(google it or go fiver) -They have had several adsense application denials and so they have finally studied how the bot works.
they are damm good!
