Michael Gray writes an interesting post about that teaching advanced link building and PageRank will never die. In the article, he explains that everyone who learns about optimization techniques are at different levels; some are more advanced and may consider topics to be basic. Now what happens if you recommend link building tactics from an "authoritative" site? By whose metric? If you apply this to authority as determined by "PageRank," Michael has a problem with this. Google's toolbar PR is simply used for "entertainment" purposes, as he says quite eloquently:

Since google has admitted that they will adjust/manipulate page rank of sites they believe are selling links, and those adjustments will trickle down/out, page rank is really just for entertainment purposes.

Therefore, Michael explains that establishing authority must occur by looking at the other available metrics together.

His post is discussed on Sphinn where Michael is forced to justify that PageRank is used now because " people need the ability to explain/understand things quickly, especially those who aren't entrenched in the field." And for that, PageRank is the current metric that delivers.

But some people have a problem with Michael's suggestion that one should refer to authoritative sites. Instead, the emphasis should be on relevant sites, be them authoritative or not. However, one points out that "relevance is a red herring," especially if the links to "relevant" pages are pornographic or questionable in nature.

Forum discussion continues at Sphinn.