The author is obviously using hyperbole to make a point as to how he views each method. For those new to these ideas, don't take the shade of gray too literally. It's still easier to classify each as white or black.
NOT true, NOT. high PR outgoing links are as effective to SERPS as PR 0 outgoing links, the difference is that the page you reffer will not get a good PR. If you want good outgoing links then just look for the same page content as your reffered page, PR is not important, I have tripled tested this and PR links are good just for PR, not for SERPS. For example http://www.flickpeek.com/ is no 3 in google for 'watch videos online', it had rank 1-2-3 for 1 year and it was NO1 in SERPS for that keyword.
On paid links and non-paid links, I don't think Google is obsessed on determining whether a link is paid or not. Unless, of course, Google would index one's Paypal payment history. No one will know of paid links because naturally a website should have links going out and should have inbound links. That's the total concept of website - link in, link out.
You've never heard of blog spam? Article marketing is pretty white hat but the problem is that Google didn't introduce the algo so that webmasters could boost their own link profile by posting articles on article sites.
My understanding is that a variety of factors (over 200?) are used to calculate the final rank of a page for a given keyphrase with the PageRank of the linking page, it's theme's relevancy, the presence of keyword in the anchor text and destination page, how well each page is optimised for the target keywords - for example, are they featured in the titles, descriptions and body text - whether the link is reciprocal, nofollowed, has reinforcing title and alt text, the links age, each pages respective age and several other factors besides. Because PageRank is just one of many contributing factors you won't necessarily see a direct correlation between the PageRank of a given page, or indeed any one link to it, and its rank for a particular keyword. Also, I believe that it's possible for Google to hide a site's PageRank display in the toolbar without actually deleting its PageRank. That's why it's possible for some sites without apparent PageRank to rank well, as if their PR was really zero then they wouldn't rank at all. Google can of course also implement a manual ranking penalty, if desired, but that's seperate issue.
The definitions you have posted will help many new understand the different terms and operations of each. Thanks for the Post. Good Pluck
This is from here The most famous part of our ranking algorithm is PageRank, an algorithm developed by Larry Page and Sergey Brin, who founded Google. PageRank is still in use today, but it is now a part of a much larger system. Other parts include language models (the ability to handle phrases, synonyms, diacritics, spelling mistakes, and so on), query models (it's not just the language, it's how people use it today), time models (some queries are best answered with a 30-minutes old page, and some are better answered with a page that stood the test of time), and personalized models (not all people want the same thing).
Article submission and blog posting are grey hat, because how black or white hat they are depends on how they are done, not on the approach itself. For example, posting well written articles to a handful of article sites is white hat. On the other hand, using a robot to post 100 close 'variations' of an article created by grammar mangling software, after scraping the original article from a genuine website, is clearly well over to the dark side, even it is technically still article marketing. Equally, Google estimates that up to a third of all web spam (at least in English, if not Chinese) is generated via free blogging platforms such as Wordpress and, ironically, their own Blogger site. As such, while many blogs contain unique, interesting content there is a sizeable number that have been created by rehashing other sites specifically to gain free search engine traffic and then cash in on their AdSense advertising, probably at Google's expense. Granted, most techniques can be done in a more white or black hat manner, depending on the person involved, but I do think that some approaches are inherently more risky or open to abuse than others.
These are great tips for everyone. I know I learned a few things that I surely will apply to my marketing g=for now on. Thanks Bruno