Forum Moderators: Robert Charlton & goodroi
If you go deep enough into any set of search results right now, you'll find a ton of sites that don't say no-cache that don't have a "cached".
The first result for "fuzzy blue widget", a webmaster world page, of course, doesn't have a cached link. Why not?
My theory is that Google is so messed up right now that they actually don't have a reasonably dated cache of that page.
Try any 2-4 word term and they're all over the place.
The fewer the results, thus the more niche the page, the less cache links they have.
I'm thinking that this may be because pages that are far down in the serps are likely to have fewer inbound links. The last time I checked, "similar" pages (those defined by the related: operator) were pages that have inbound links from the same source. There are probably other threshold factors as well.
As you go further down in the rankings, therefore, it would seem that you're going to a sparser part of the link graph, where the likelihood of shared link sources is less, and the reporting of "Similar" pages is also less.
My guess is that with caffiene, they are replacing "cached" with "8 hours ago" (seen this one back again yet?), and if the date is older than xx, they just show nothing.
(edit) I should add, that I have a site around 4 months old.
[edited by: tedster at 5:16 am (utc) on Jan. 8, 2010]