PR is a terrible way to judge link quality for SO many reasons:
- Penguin
- The fact you can easily fake PR
- The longer you go without a PR update the more this metric becomes unreliable.
- Did I mention Penguin?
You can look at SEOmoz scores, search engine results and any other metrics you want. But
only PageRank will tell you if a site has been penalised for actually passing juice at the end of the day.
For example, take a look at jenn/dot/nu. SEOmoz scores look good. Lots of backlinks. Ranking in search engines. Yet PR is 0. I've watched that site over the years and it's been repeatedly penalised for link juice benefits because of paid guest posts and the like. PR is the only metric that will tell you that. There are plenty of sites with great backlinks that have been banned from passing juice completely.
The only even valid/related point in your list above is the 'unreliable' factor from the update. But realistically, the SEOmoz index is not *fully* updated that often either. I've waited 3 months for a Wikipedia link to show up in OSE for a reasonably average authority site before.
I'm *not* saying PR is the only way or the best way to measure a link's value, because of course that would be idiotic. But it would also be idiotic to ignore a metric provided by Google, even if it's just an observation rather than practical use.
The problem with SEO is that people parrot a lot of stuff. Yes, PR has its flaws, it's quite crappy compared to a lot of other tools. But you may as well use everything you've got.
If your site was "normal" would it suddenly start getting PR3+ links all over the place? Nope.
It would get slow low PR links, the odd PR3 one, and definitely zero PR5 links generally.
500 Gov links would blow your site into the darkest dungeon in Google basement never to be seen again. Unless it was old and well established in the first place.
This.
Okay so lets take a step back from a massive brand - lets say you are starting up a small clothing company (purely online) that is designed to help babies and toddlers from over heating. You launch your website that is trying to rank for baby clothing and the BBC picks up your story because of the uniqueness of your product... Then the guardian, huffington post, daily mail.... Okay so with all this press quite a few mum bloggers are keen to blog about your product as they feel it really helps and government organisations are looking to recommend it to their constituants. I guess I will just turn round and tell everyone not to link because supposedly this will punish my site?
That's a different situation. If you attract so much interest from high authority places, it's more likely you will continue to do so at that level (you will have bloggers, forum posters etc. linking to you as the new wave following the initial press interest). Most people building lots of links to a new site throw hundreds/thousands at it for a few weeks and then stop building altogether. That's not natural.
Anyone who thinks that a huge number of legitimate quality links over a short period of time are going to punish a site frankly need to get back to the drawing board. This is not something that has ever been highlighted as a problem by any of the most experienced people in the industry.
You said yourself it's 'normal' for sites to bounce around the rankings. I think it's abnormal. I think that says it all really.
There are plenty of things I've seen that haven't been acknowledged by experienced people in the industry. But there are plenty of reasons for that; because they work on hugely different sites in different contexts, because they don't give away everything they know, because they don't work on new sites, or simply because people have never raised a question in a particular context.
I think the only way to settle it really is to do as controlled a test as possible.
There have only ever been a few reported cases of clear negative SEO penalties (penalties, not devaluations). To think that negative SEO can happen because you went and got 500 .gov links is absolutely bizarre.
I don't necessarily believe it's any kind of penalty. I believe a big part of it is Google trying to figure out where the hell the site belongs in the rankings because there are mixed signals.