Well - I seen the updates and heard people talking about the new rules governing ad' placement, and I learnt the hard way... Google really will punish you for placing ad's above the fold (well to many)... which is complete and utter bullshit... The main points are to have content on the top half of your screen, 75% (basically) needs to be site content, the other 25% possibly ad's... by content - I don't mean header and categories etc. I mean a majority must be post content - and your ad's can not be a focal point... For a better understanding Google is now TELLING you where to put ad's and have a set of examples for you to follow... and if you don't I can guarantee that they will catch up to you - I was penalized and lost 50% of traffic (5k visitors per day) and now I have corrected these issues my traffic is coming back again... Here's the official view and guides - per niche of your site even: https://support.google.com/adsense/bin/answer.py?hl=en&answer=187643&topic=29875&ctx=topic