I have a doubt, Why would google penalize a site for being made for adsense.
I don't know many of the answers to questions you asked. But... Adsense team is one small arm of Google, and probably has a lot of conflict with other areas of the company. Purely speculative... but I'm sure Matt Cutts is not involved in too many adsense sales goal directives.
I can't even begin to suggest what is best for you or anyone else to do, I only know what has worked for us
, our type of site, and our business. Which is different for everyone.
We removed ALL but 1 single adsense ad block per page, and its at the very end of the content, AFTER our own internal navigational links. No sidebars (they rarely get clicked anyway) no headers, no navigational ads, nothing... 1 single block is all we carry on sites now. Like I said... its what we found works best for us.
On our site(s) we only send people to adsense ads when we have exhausted our own internal efforts to answer their need.
In your case... you had:
- 1 Google adsense custom search box
- 1 468 Amazon banner in the header
- 2 link units per page
- 2 300x250 adsense blocks per page injected into the middle of your content
- 1 adsense skyscraper in the sidebar
I understand you are maximizing what adsense suggests... but just ask yourself... if you walked into your doctors office to ask a question, how happy would you be if you were approached 18-20 different times within the first 2 minutes, by salesman trying to sell you something. (All your ad boxes add up to 18-20 individual ads per page)
Also... one other "tip" about adsense... the HIGHEST bidders for placement
tend to appear highest in your ad placement. So if you have 4 separate ad blocks on the page... the HIGHEST CPC is going to be in that very first ad block, very first position
. The ones that come into the second, third and fourth ad blocks... they will have the companies/advertisers who bid pennies per click (remnants), just to be there.
We found that by showing just 2-3 ads per page, (1 ad block, with 2-3 ads) we ALWAYS
had the highest bidders on the site, and earned the highest EPC. (earn per click) Think about it... if 10 guys are bidding for the word "website" and the top one is willing to pay $10/click and the 10th guy only willing to bid .50 cents/click, which one would you want to be clicked? If its the $10/click company, why even show the others? Just place your ad in the right spot...
As far as how long it takes a site to recover... if Google is still sending you search traffic, just start experimenting. When you DO finally get better pricing again (1 day, 1 week, 1 month, 1 year, whatever it is), AVOID the temptation
to push more ads, and soak more money back out! Been there... done that... it will only get you smart priced again!
Adsense is not about having the most content and the most ads on a page, hoping to lucky-dog your way into a click... its about having the "most relevant content to the reader", and the "most relevant and highest bidding advertiser" to appease their need.