Many blogging software packages automatically nofollow user comments, but those that don't can most likely be manually edited to do this. This advice also goes for other areas of your site that may involve user-generated content, such as guest books, forums, shout-boards, referrer listings, etc. If you're willing to vouch for links added by third parties (for example, if a commenter is trusted on your site), then there's no need to use nofollow on links; however, linking to sites that Google considers spammy can affect the reputation of your own site. The Webmaster Help Center has more tips on avoiding comment spam39, for example by using CAPTCHAs and turning on comment moderation.
Despite this many people seem to get it wrong! In particular “Chris Ridings of www.searchenginesystems.net” has written a paper entitled “PageRank Explained: Everything you’ve always wanted to know about PageRank”, pointed to by many people, that contains a fundamental mistake early on in the explanation! Unfortunately this means some of the recommendations in the paper are not quite accurate.
In essence, backlinks to your website are a signal to search engines that others vouch for your content. If many sites link to the same webpage or website, search engines can infer that content is worth linking to, and therefore also worth surfacing on a SERP. So, earning these backlinks can have a positive effect on a site's ranking position or search visibility.
It is interesting to read the article which however as others have commented leaves questions unanswered. The ideal internal page rank flow is clearly down the hierarchy and back up again evidently and no page to page links down the line. If this effect is big enough to have provoked an algorithm change then it must be substantial. Removing those related product links altogether would improve ranking and degrade the user experience of the site which surely is undesirable. I suspect the lesser of two evils was chosen.
We have a saying that “good data” is better than “big data.” Bid data is a term being thrown around a lot these days because brands and agencies alike now have the technology to collect more data and intelligence than ever before. But what does that mean for growing a business. Data is worthless without the data scientists analyzing it and creating actionable insights. We help our client partners sift through the data to gleam what matters most and what will aid them in attaining their goals.