Subpage PR4, No PR increase on Homepage - what gives?

[AdamThompson]

This subpage gained a PR4 (was PR5) from external links. http://tinyurl.com/a24ghh9 It only has 5 links, including 2 links to the site's homepage.

The homepage was PR2 before this subpage was published, and still is even after 2 PR updates. I'm surprised the PageRank that should be flowing from this subpage to the homepage hasn't increased the homepage PR to at least 3.

Assuming each level of toolbar PR is 10x the one before, a PR4 subpage with 5 links should pass more than enough PR to the homepage to bump it from PR2 to PR3, right?

Any ideas?

Does Google have a really strong decay on how much PR gets passed from subpages to homepages?

This is somewhat troubling to me, as it poses a problem for the "attract links to your content pages and your homepage and money pages will rise with the tide" approach.

[Backlinko]

Ahhh, I see what you're saying Adam.

I looked at the infographic page and the 2 links pointing to the homepage should send some PR to your homepage. So I doubt that's the issue.

One PR4 link isn't enough (even with the low OBLs of that page) is enough to bump a PR up from 2-3, at least in my experience.

It still may not be juuuuust not enough to show up on the toolbar. You could have literally gone from PR2.1 to PR2.9...almost there but not enough.

[AdamThompson]

"Remember that PR is semilogarithmic...each is not 10x the one before...it's often 1000+ times. This means it takes a helluva lot more PR to go from 2 to 3 than it did to go from 1 to 2."

That is exactly my point! A PR4 is exponentially more than a PR2, so 1/5 of the PR from a PR4 page should be more than enough to bump a page from PR2 to PR3.

Unless PR4 is <5x PR3, 1/5 of the PR from a PR4 page should be enough to make a page PR3. (Or am I misunderstanding the math?)

The only explanation I can think of is that for some reason, 1/5 of the PR from the PR4 is NOT flowing to the homepage (the PR2 page). And that is what concerns me.

[Backlinko]

Simple answer to this: your homepage PR probably DID go up...but not enough to push it to PR3.

Remember that PR is semilogarithmic...each is not 10x the one before...it's often 1000+ times.

This means it takes a helluva lot more PR to go from 2 to 3 than it did to go from 1 to 2.

And keep in mind that there are hundreds of "partial PR" permutations not shown in the toolbar. So maybe when your homepage first showed PR2 it was PR2.2. And the PR4 link pushed it to PR2.8.

Not enough to show PR3 quite yet.

[EGOL]

The two possibilities that I see are.....

A:  The links that hit Page A have higher pagerank than the sixty links that hit Page B.

B:  The published pagerank for Page A and Page B are not of the same data vintage.

[AdamThompson]

"So spending time trying to understand why Page A is PR5 with six links and why Page B is PR4 with sixty links is not a good use of your time"

Usually I pay scant attention to toolbar PageRank. In this case, I'm wondering if what I'm seeing represents at a broader, important concept, so I want to understand what might be going on in this situation better.

[EGOL]

One of the best ways to understand PageRank flow is to spend some time playing with a tool like this.  Once you have that mastered you can build an excel spreadsheet that will calculate it one-step-at-a-time.

PageRank is published "for entertainment value only".  So spending time trying to understand why Page A is PR5 with six links and why Page B is PR4 with sixty links is not a good use of your time - as long as you understand the basic concepts of how it flows.