I'm revamping an old old site that was linked up back in the day of "more links = better". I'm going through the (about 1500) links and notice a lot of links that just aren't desirable these days; online pharmacy, mlm, gambling, etc. This got me to thinking, what exactly are the undesirable neighbourhoods from a co-citation standpoint? Obviously this is subjective depending on what sector your site is in, assume an innocent, traditional product-vending site that doesn't want to be linked to the "seamier" neighbourhoods. Keep in mind that this isn't a moral judgement on my part, there's a lot of bad neighbourhoods you don't want to be associated with simply because SEO competition in them is so fierce that the tactics are entirely blackhat. This is what I've identified so far; please let me know if you agree, disagree, or have other potential categories to add: - gambling - dating, online dating, casual encounters - MLM in any flavour/"earn $$$ from home!"/affiliate businesses that only exist to create affiliates - Mortgage/refinance/cheap loans/credit check service(? not sure about this one) - Real Estate (if not in the real estate business) - Pornography of any stripe - online pharmacy/rx/"research chemicals"/Viagra/Cialis - mesothelioma - free automated Link exchange services If you run any of these please don't take this as an indictment of them. I've read in several places that the quality of your link neighbourhood can affect your categorization and the link strength of inbound links. While I can make some informed guesses (above) I was wondering if anyone had anything more specific. Here's an explanation of the co-citation effect: http://www.jimboykin.com/co-citation-understanding-how-it-effects-your-seo/ (note, not Jim Boykin or affiliated with him in anyway)