You'll all notice that the article does NOT say $10,000 per Month or per Year or over ANY period of time. Could be lifetime.
The best convertion you will get is organic traffic from google . I have bought 5000 hits for 20$ and earned a small little like 2.3$ from adsense with a ctr of less than .5% .
You are a lucky one usually, the traffic you buy is the auto-generated traffic meaning that humans do not see your site, only bots So, having a .5% CTR and making 2.3$ from that traffic is quite good IMHO. Of course, you could have made the money not from the traffic you bought, but from the traffic that came to your site naturally - you cannot really prove that the purchased traffic visitors generated clicked on your ads
The basics: Content and Traffic. If you can sort those two out then tweaking your Adsense placement and presentation is like going back to 1st Grade.
"Instead smart webmasters have found that using the Large Rectangle (336x280) yields the best amount of click-thrus. " I totally agree to this one. 336 * 280 works best for me.