martinibuster - 2:42 am on Aug 26, 2013 (gmt 0)
If it has a PR of over 4 I feel relatively safe linking to it...
That's the PR 4 Fetish. Do you know where PR 4 gained it's importance? Many years ago the backlink search only showed links from sites PR 4 and up. That was an arbitrary choice by Google. The intent of the backlink search was just to show a random sampling. So, unaware of how web publishers would use the information, the Google engineers randomly chose PR 4 as the threshold for sites seen in the backlink search.
But it backfired because it gave birth to the SEO Myth that PR 4 and above is a sign of quality. The reality was that there was no magic to PR 4, it was simply a random choice.
Dave Naylor mentioned to Matt Cutts (at Pubcon London 2003) that a true sampling would show a mix of PRs, and that the current system caused discrimination against under PR 4 sites. Matt agreed and brought Dave's suggestion back to the Googleplex and the backlink search soon returned a true random sampling of sites.
Unfortunately, the PR 4 Fetish remains to this very day, even though SEO people no longer remember why PR 4 became a metric. You really should stop using PR 4+ as a metric because there is no basis for believing a site less than PR 4 is not worth linking to. It's a mistake to dismiss sites less than PR 4.
If you truly want to be successful, adopt solid practices. Try to understand the true reasons behind certain marketing practices. I hope this information helps you make better decisions. ;)
The day may come when the Toolbar will disappear and I truly fear a future when web publishers rely on non-Google toolbar ranks to make linking or marketing decisions. That's a lot of power and influence to hand over to an SEO company or a Tool seller.