Before I get into another below, I just want to say that Google ranks individuals documents - or pages - so yes they all carry importance.

On the same hand, you can also control pagerank's flow and anchor text application by using all of the pages on your site effectively - so this only bolsters the importance of each individual page.

This is an interesting post... And for a few reasons.

A) Is it really the case that you want your "strong" pages to link to your "weak" pages as an effect of distributing pagerank judiciously? (pagerank being the reason one page is strong while another is weak)

B) Or should "weak" pages be used to strengthen certain pages (or make them stronger) for both better search engine ranking for those terms and as a means of primary navigational importance? And on the same token, these "weak" pages can still be linked to from the 'strong' pages and donate a well optimized subheading tag to that 'strong' page only allowing it to rank more easily for additional longtail traffic itself.

I understand this might be a little confusing, but that's because I'm attempting to differentiate two different ways of looking at the same issue.

Let's talk category pages with Wordpress.

They can hold significant content and every page that they link out to will typically be done using a H3 (sometimes H2 or H4) subheading tag. While this might be looked at as a 'Strong' category page linking out to 'weak' longtail pages - I'd venture to look at this through another lens.

If that Category page was strong in terms of content and other on-page SEO factors, all of those closely niched and related subheading tags would likely contain variations of the primary keyword phrase targeted by the main category page. What you are really creating with that category page now is a 'Source Document' that (when assembled properly) contains useful and relevant information to answer queries related to a specific search term and secondarily is also optimized through effective use of subheadings which are filled with longtails and variations of the primary keyword phrase the main category page addresses.

IE - you now have a strong document for ranking - BUT - it is actually the page that benefits from those other 'weak' pages that it links to, if for no other reason than the efficient use of subheadings.

And it get's better...

Assuming that your category is titled in such a way as to attempt to rank for a specific keyword phrase (and associated longtails), ever page that was linked to from that main category page will link back to it with an optimized anchor text only more strongly identifying with Google what that main category page should be ranked for.

IE - Now that main category page is not only benefiting directly from the well optimized subheading links to the other 'weaker' pages, but now it is also getting an anchor text optimized link back to it from each of those pages which means that it is the 'weaker' pages that are actually strengthening the 'strong' page in two ways now.

Example:

Category Name - (H1 Heading) White Hat SEO
Links to Pages Titled:
(H3 Subheading) White Hat SEO For Beginners
(H3 Subheading) White Hat SEO Techniques That Work
(H3 Subheading) White Hat SEO Linkbuilding Methods
(H3 Subheading) White Hat SEO Tools
(H3 Subheading) The White Hat SEO Rule Book
(H3 Subheading) Why White Hat SEO's Have It Right
(H3 Subheading) Hungry? Then Get White Hat SEO. It's What's For Dinner
(H3 Subheading) This White Hat SEO Is Laughing His Way To The Bank
etc etc etc etc

Now that main category page has a lot of subheading tags on it that all contain the term 'White Hat SEO' or very close variations of it, which will be beneficial if that is the search term you are trying to rank for.

In addition, every one of those will link back to that category page with the anchor text 'White Hat SEO.'

So assuming that we are in a link-sterile condition (no inbound links) the reciprocal links between the two pages should hypothetically be a zero net benefit in either direction.

HOWEVER, it is the main category page that is getting the benefit of all of the subheading tags and the very specific anchor text optimized links back to it.

So - this is where I question... is it the case of the 'strong' page benefiting the 'weaker' pages, or is it the case of the 'weaker' pages actually doing double duty to strength the 'strong' page?

Now Equally....

Someone could make the argument that the category page will be linked to from the navigation menu, and Google heavily favors pages that are included in primary navigation. Further more, there may be an unequal pagerank distribution associated to those pages based on the fact that they are on the primary navigation menu, so it's really the links from those category pages to the other pages that is the main benefit.

To that, I would say there is certainly a strong argument to be made for that position. However, that only if we are looking at internal pagerank flowing one way and not taking into account the benefits of the subheadings, and not to mention that the internal pagerank will be split up among all of the links out to those 'weaker' pages within the category, where as those 'weaker' pages may only be linking back to the category page and/or closely associated tags (which will serve a similar purpose in a dual plane silo.)

So....

I've rambled on for awhile.

I'm not attempting to say there is only one way to look at the issue. The opposite is actually true. I'm saying that there are several ways to look at the issue of internal link distribution and ultimately it is up to the individual operator to decide for themselves how to leverage it properly based on their content strategy.

FWIW, I keep the mindset and develop my content strategies around the idea of ranking the category (or 'stronger') pages for main keyword phrases and many associated longtails while the 'weaker' pages merely serve to suck up stray secondary terms while primarily contributing to the benefit of that main category page - as it will often be where the money is really made and responsible for turning a user into a customer.

If your category pages were covering very general topics, such as "SEO" instead of "White Hat SEO" then I would probably flip my point of view and depend on the 'weaker' pages to do most of the heavy lifting and develop my content strategy with that in mind.

How many people did I just confuse?