I found this short but yet enlightening discussion in the Google Webmaster Help forums about what percentage of inorganic links you need to remove to probably have your inorganic link penalty removed.
An inorganic link is based on a Webmaster Tools notification of a site buying or acquiring links in a none natural fashion. Many webmasters have been receiving them recently and many want to know how to reverse the action.
We know these are manual penalties, at least if you received the webmaster tools notification. So you need to go through the inorganic links and do your best to get them removed.
In the thread, the webmaster said he was able to remove 85% of the inorganic links and asked Google if that was a high enough percentage to submit a reconsideration request and for that request to be satisfied. Google's John Mueller implied yes, it was enough.
John from Google said:
With 85% resolved, it sounds like you've covered a lot of ground already! If there are links that you're absolutely not able to remove, I'd document that with a reconsideration request along with the issues that you've been able to resolve.
So I guess if you can get rid of about 85% of your inorganic links and explain why you can't remove the others, Google might forgive you?
Forum discussion at Google Webmaster Help.
Image credit to BigStockPhoto for % sign

Comments:
Paul Chaloner
06/13/2012 01:03 pm
You'll also have 85% less backlinks going to the site which in turn means drops in rankings anyway, you lose either way.
Mark
06/13/2012 01:35 pm
Doesn't this state removing 85% of the inorganic links... Not your total link count... So in essence if 30% of your links are S**t you are only removing 85% of that 30%... If you have been penalised this post states removing the crap links will help, at least removing 85% of the crap links, not 85% of your total links. If you have been penalised you won't rank. So surely removing some of your crappy links will have some benefit. Because.... You have already been penalised... lol. So does adding more links on top of crap links, even after you have recieved a notification, fix things? The only problem with this that I can see, is identifying the Inorganic links, which takes time. :)
Oleg Korneitchouk
06/13/2012 02:11 pm
Removing 85% of any links (especially low quality ones) is a huge challenge (it took this guy 3 years) and I think this guy will definitely see his penalty lifted. Especially now that we know Google grants partial penalty revocation, it would probably be a better idea to have submit the request even earlier.
Webstats Art
06/13/2012 07:18 pm
Who has time to play these kinds of games anyway?
AlokCCF
06/13/2012 08:22 pm
It would be interesting to see some concrete evidence of search rank changes when removing a % of inorganic links. Does this mean you'll automatically be promoted when you remove the inorganic backlinks?
Alan
06/14/2012 04:54 am
Paul has hit the nail on the head. If you have taken away 85% of links why not just start again. There are ways to move the content to a new domain with little or no penalty being transferred, why bother with egtting links removed?
emikey
06/14/2012 10:06 pm
What if most of your links are directory submissions? How can you get those removed?
Sigh
06/15/2012 04:41 am
Sounds like they are encouraging Negative SEO. Thanks Google.
Lord of SEO
06/15/2012 05:53 am
lol wtf
Lord of SEO
06/15/2012 05:54 am
google is a joke company --------- bing it
umerseo
06/17/2012 10:19 pm
What if we don't receive any notification in our webmaster but still receive bad penalties in the rankings ?
Tim
06/18/2012 01:45 am
inorganic google - i cannot believe what that guys become N1 in search. only because lack of competition.
Google
06/18/2012 01:46 am
remove only sitewide
Andy
06/18/2012 02:07 am
them indexing web or test them for inorganic? search engine is search engine, it not a task of webmaster. it can come what we need to even review google results themself to get credits for our site ranking. good idea, google pay me commission!
lee
06/18/2012 02:08 am
because you can see a patterns.
Ori_Zilbershtein
07/01/2012 01:29 pm
this is idiotic, many sites i know have unnatural links or inorganic links but they still do well in SERP'S. and i know other sites who did no Wrong or at least didn't do aggressive SEO and they got penalized