Making money from websites has been getting tougher for years - that's why I took a year out to look at other things
I'm back - not out of choice, but because everything else is just as tough
Re. what you've been doing - nothing really wrong, but I'd just have the large rectangle and dump the other 2 adsense blocks - highest paying ads appear first - then next lowest, then lowest - so 3 blocks is giving option to click on low paying ads
I had a forex autoblog that paid about $40 a day adsense from 4,000 visitors - so CPC of your sites may be poor - nothing you can do about it now except build some higher paying sites
Adsense team blocked the site because of a youtube video that got auto-posted - so I switched to CPA adverts - income fell to about $30 a day - so adsense was better
I also sold banner space on the site - paid well, but could never keep advertisers long term
I dumped all my sites and walked away in the end
I've gone back to site buiding for clients, but I'll soon start building large-scale web 2.0 CMS portal sites, and large-scale xsite pro static sites for myself as well
I'll never, ever, build another wordpress blog, or static micro-niche site - it's clear you've got to go BIG now to get the Google traffic - exception seems to be blogger blogs, as Google is favoring its own sites