I have asked on a few occasions the appropriate manner to treat external advertising on a website, but have not found a satisfactory answer.
On the Google site, you are encouraged to report "paid links," which I assume could include normal advertising, using the "no-follow" attribute, but many claim that this is essentially ignored via their algorithm and is really only subject to manual review.
I try to be above-board and report all paid advertising. Is it worth the time and is there a possible penalty in having many nofollows due to having many legit ads? And if an external site link is paid for on one area of the site, should it be nofollowed in other areas when it is part of normal existing content and recommendations?
I am not talking about site sculpting or the like--which I do not agree with--just conformity with the rules regarding using nofollow for ads (some call them paid links, but not all advertising is a paid link--in fact this in the case on many sites).
Thank you.