backlinks not shown

backlinks

[westonmoore]

i have been extensivly scanned by google since overhauling the website of my new employer, and went from a PR0 to a PR3 during this last update. many pages with high PR responded to my requests for links, but despite the cache of my page reflecting recent changes, the backlinks are non existent, any ideas?

[tigger]

for the links to show they must be a PR4 so check out what they are

P.S Oops sorry welcome to WebmasterWorld :)

[westonmoore]

thanks, long time reader first time poster :) but i have been engaged in site development focused on search engine placement for 5+ years. (not advertising, defintely here to learn from you gurus)

quick checks reveal 2 PR5 with the link shown in cached page?!?!

A PHP site from a .edu that google recognizes contains the term, but has no cache of the page despite being up for years and a major page for the topic with PR5.

a PR4 from a great site that has linked for about a month not that oddly the link is not reflected.

i could go on but i dont want to bore you.

[westonmoore]

i think i have identified the confusion, for backlinks to show my site must be above a PR4 irrespective of the rank of the pages which link to me, is this correct?

[soccer_star]

That is correct :)

[MyWifeSays]

The cache doesn't necessarily reflect the backlinks that Google is using for calculating PR.

Google crawls the web over a period of about 3-7 consecutive days within a month to create the link network that is used to generate PR. This is referred to as the deep crawl. Google then starts to use this data about 3 weeks later on the next Google update.

The cache for a page can be updated by Googles FreshBot at any time within a month.

This means that if a link is added just after the deep crawl it can be seen in a pages cache if the freshbot has visited but it will be approx. 7 weeks before this link will be included in the PR calculation.