I've been reading people saying how if a certain 'ad' performs badly how they block the 'site' to up their CTR.

I'm presuming they are talking about the ability to block certain sites from showing up in your AdSense ads, for example the site of a competitor or just a 'low performing ad'.

I can't seem to figure out where the heck these reports are, all I can see pretty much is clicks, impressions, ecpm, etc. I can't find any details on which ads were clicked on and moreover, how to block certain ones

I searched the helpcenter but no luck since i'm not entirely sure what I'm looking for :/

help!

I don't think you can get reports on what ads were clicked, you can block advertisers by their URL, if you see for example ebay ads on your site, ebay often bid under very cheap keywords like "Jim is here" with an ad that says Buy Jim is here on ebay or similar, those ads are not going to 1) perfom well (who want to buy Jim is here?) and 2) pay much - ebay seek out ultra cheap key words.

To block ads go to: AdSense Setup - > Competitive Ad Filter

and enter urls, subdomains etc as per the instructions.

I don't know how people determin low paying ads by the reports though, unless its using chanels for certain pages and seeing what ads appear on those pages - but even that would be a bit hit and miss.

Thanks!