Models of google pagerank, or, is it smart to openly link based on pagerank?

[Halfdeck]

Same thing with buying high PR links. Why? Well, IMHO if you master a few other things and get high pagerank, you can pretty much place high for just about anything you want.

You sure can - especially if you're a big company with millions of bucks to play with. A Walmart-affiliated company skyrocketed to #1 in local UK results for "car insurance" by paid links alone in the span of just a few weeks (Why target UK results? Biggest piece of the pie for that term, according to Google Trends).

Inadequate paid link detection is arguably the biggest hole in Google's algorithm right now. Link exchanges are less of a problem for Google because they are much easier to detect than one way links that are bought and sold.

People who trade for PR tend not to care if the page they are trading with has any relevance to their own page.

Relevance is a big factor but if links are traded its still only one step above trading for PageRank. (Not saying trades are necessarily bad. You can trade up to TBPR 5 or so and then install a semi-sex related blog to pull mainstream/organic links into your domain to round out your link profile).

Linking to quality sites is also a weak strategy if the link is part of a trade. In fact, site quality in adult doesn't matter all that much in terms of search until we have people linking out freely. Unfortunately, affiliate sites linking to the competition freely just makes no business sense.