I tend to agree with about half of what you are saying. I have never seen anything that leads me to believe that so-called “Domain Authority” that you and many others speak of as anything separate or different than PR.
We never get to see a page’s true PR score, only a rounded number on the toolbar based on a score that could be as much as 3 months old. All in-depth analysis I have seen indicates that the “Domain Authority” performs in a fashion identical to PageRank. Even if they are separate entities, there is no reason that I have found to look at them as such.
As far as how and why profiles work I think we have very different theories. While we both agree they work, we have a fundamental disagreement on how and why they work.
I see that the relevance of your backlink from profile pages, or any other web page, weighted by PR, influences your pages relevancy score. You seem to think that some sort of “Domain Authority” value pushes your page ranking higher.
I believe the root of our disagreement centers on whether search engines rank individual documents, or instead, websites. If we were to agree on which of these are true, we would have no other disagreements on this subject.
I have spent years studying the design and implementation of large scale search engine technologies. In all those years of research and development work, I have never seen any search engine data structures that indexed websites rather than individual URLs.
In fact, the primary difference between a website directory and a search engine is that directories usually index websites while search engines index individual pages. This is what makes the search feature of a search engine so much more appealing than the search feature of a directory. Search engines take you to the most relevant page it can find while directories generally take you to the website homepage.
This difference between search engines and website directories is key to Google’s success and in my opinion, the reason that they will never shift away from the basic principle of indexing individual pages rather than websites.
Mike, I believe if you ever come to see and understand this basic difference, it will spark a paradigm shift in your viewpoint.