• Register
• Log in

SEO Theory - SEO Theory and Analysis Blog

Algorithm analysis, Web community relationship analysis, SEO practices and techniques, industry news, etc.

• Home
• About SEO Theory
• SEO Glossary

New SEO definitions to ponder…

Posted by admin on January 20, 2007 in SEO Metrics, SEO Theory

I figured I’d better write these down somewhere or I’ll forget them and someone else will coin them first. (Note to Blogger: Please give us smilies so I can include :rolleyes: )

Well, anyway, as other SEO bloggers are starting to talk more and more about cache dates (which Google rendered useless for Webmasters in September 2006), I might as well say a little more on the topic myself.

The Google cache is a very useful tool for a number of reasons. It’s not useful for telling you when Google last visited your site because it doesn’t really tell you that. Did Google undo their change of last September in response to considerable complaining from me and others, or did they not implement it, or does it not work as described in Vanessa’s post? I can tell you, for example, that Xenite.Org sees multiple Googlebot fetches of both fresh and stale content that never make it into the cache.

And I have some pages whose cache images are updated several times a month in Google. It’s just that that cache dates don’t reflect how often Google visits or finds new content. Take that for what it’s worth.

Even so, as Toolbar PR lovers continue to get their outdated ideas bashed, thrashed, and beaten to death by a growing number of clued-in SEOs, the community is looking for new ways to evaluate trust and value. Again, let me point out that my current employment contract restricts what I am allowed to share on this blog. Still, let’s see if we can identify some usable ideas and terminology.

Definition: Crawl-to-Cache-Time - CCT is important for Webmasters who need to know how long it will take for their changes to show up in Google’s index. Keep in mind that there is also…

Definition: Cache-to-Ranking Latency - CRL is the length of time it takes a new Google cache image to be reported in ranking queries. Can you have two cache images in the index? Yes. You may see older cache images on some data centers. And you may occasionally see your cache image in the Supplemental Index. So far as I have been able to determine, every page that is in the Main Index is also in the Supplemental Index.

Impatient Webmasters may just want to cut to the chase with:

Definition: Crawl-to-Ranking Time - CRT is really what we’re looking for. Pages that have short CRTs most likely have a lot of value in the search engine’s estimation. If you can rip your eyes away from the Google Toolbar for a moment, there may be a correlation between Internal PageRank (which is NOT reported by the Toolbar) and Crawl-to-Ranking-Time. Or not.

Definition: Crawl-to-Passed-Value Time or Crawl-to-Passed-Value Latency - CPV Time or CPV Latency is how long it takes from when Google finds a link on page A for page B until page B reflects the passed value in Google.

These ideas don’t just apply to Google. You can pretty much assume they apply to all the major search engines. In fact, you can develop some metrics by looking at averages, minimums, and maximums. Such statistics will tell you how strong your pages are across the search market, how strong your supporting pages (the pages that link to your content) are, and where you need to improve your navigation and/or inbound links.

You can also look at:

Bow-to-Stern Latency - BSL is the length of time it takes a search engine to cache your deepest content after the last time it cached your root URL. BSL may show occasional drops if you get deep-crawled, where a spider tries to grab as many pages from a site at one time as it can. On a large site deep-crawls can last anywhere from several hours to several days. They can be very, very painful. I assure you I’ve been through more than one and I don’t like them.

Measuring BSL is not easy because your root URL may be cached several times before your deepest page is. And understand that you cannot match cache dates from the Main Index with cache dates from the Supplemental Index. You’re looking at two separate indexes, each of which uses its own crawlers.

Other search engines may implement dual-indexing methodologies. Inktomi, which Yahoo! bought a few years ago, used to maintain dual indexes. You needed to be in the main index in order to rank on any Inktomi-powered search engines, and getting there was not easy (until we invented link farms).

Frequently cached pages will become highly valued by link builders. They will want links from those pages. Understand, however, that the engineers at Google (and other search engines) aren’t blind and they aren’t stupid. If they are not looking at linking profiles of frequently cached pages already, they will be (especially after they read this blog).

Moderately cached pages will probably become the real power-players in third-party SEO. Off-page optimization extends beyond linkage, but as link-builders become more sophisticated they won’t have to understand all the factors that influence off-page optimization. They’ll just know they like what they see. Moderately cached pages cannot flood the index with spam, frequently cached pages probably won’t try, and rarely cached pages will most likely be ignored by link builders.

So, how often does a page have to be cached for it to be a frequently cached page (FCP)? I think you should define your own metrics. But we all know that some pages are cached every 1-2 days, some pages are cached every 1-2 weeks, and some pages are cached every 1-2 months. Anything else is probably only showing in the Supplemental Index on Google (but don’t hold me to that — it’s an off-the-cuff guess).

So if you soon start seeing people talking about VPPs (Value-Passing Pages), FCPs (Frequently Cached Pages), CCL (Crawl-to-Cache Latency), and CRL (Cache-to-Rank Latency) you’ll know they have been reading my blog. Regardless of what they call these concepts, I think we’ll see more and more people looking at Web resources with a more critical eye for performance.

Google has pretty much forced that upon everyone. You cannot measure Internal PageRank, but you can measure just about everything else, one way or another.