How to gain from Google Adsense

Wanna get very high CTRs? You need to make a really excellent website. It maybe take a year's work to build it up and make it fantastic, full of really good content and with hundreds of backlinks. But Which type of websites will generate more adsense revenue?

To answer this question, here are some guy very helpful website building experience, enjoy it:

Forums - low return, hard work to get started and established.
directories - ok return, but needs programming skills.
blogs - anyone can start one, good return, but you've got to have ideas and opinions and writing skills.
portals - lots of work but should be good return if you can make it popular.
myspace - I don't know.
classified ads - lots of competition, same with dating sites. You should get a very mixed bunch of people coming to your site, so plenty of ad clicks.
tutorials - good for getting traffic as this is good content. Should get a good return if your ad positions are good and relevant. Hopeless for computer tutorials though as techies don't click on ads. Believe me.
article websites - similar to blogs and tutorials. Can you write well?