10. Temporal Link Growth Measurements
Since Google released its patent application on historical
information in March 2005 (read more at http://www.seomoz.org/article/google-historical-data-patent),
search marketers have recognized that trends in temporal link and
content analysis do have a real impact on rankings.
The engines are trying to measure patterns—they’re looking for
indications of increasing or decreasing relevance and authority that
temporal trends provide. They want to identify several specific
items:
Content growth patterns
How often does a particular site tend to add new
pages?
Content update patterns
How often are documents edited and updated?
Link growth patterns
How often do new links appear pointing to the site?
Link stagnation patterns
Does the number of links to the site stagnate or
decrease?
The engines aren’t interested only in how many links pointed to
the site today versus yesterday (or how many pages were added); they are
also fundamentally interested in tracking patterns over time. Figures
Figure 35 and Figure 36
depict some example graphs showing the rate of new external links (and
in the last two instances, pages) created over time, with some
speculation as to what the trends might indicate.
These assumptions do not necessarily hold true for every site or
instance, but the graphs make it easy to see how the engines can use
temporal link and content growth information to make guesses about the
relevance or worthiness of a particular site. Figure 37 shows some guesstimates of
a few real sites and how these trends have affected them.
As you can see in Figure 37, Wikipedia has had
tremendous growth in both pages and links from 2002 through 2006. This
success manifests itself in the search engines, which reward Wikipedia’s
massive link authority with high rankings for much of its
content.
Meanwhile, as shown in Figure 38, DMOZ has experienced a
relative decline in popularity. Although DMOZ was once a default
reference link for many sites, its relative influence has waned. It is
likely that its traffic has declined in a similar fashion.
Many forms of spam and manipulative link building are likely to
stand out like a sore thumb when put under the temporal microscope. When
a large gain in links relative to a site’s sphere, influence, and
historical link growth appears, the engines can take a closer look at
the source of the links or even trigger a manual review. Common sense
would dictate that a small-time local real estate site doesn’t usually
attract a few thousand new links in a week unless it has done something
newsworthy or linkworthy.
There are few limits to what the engines can do with data such as
this, and there is no reason they shouldn’t be analyzing it (since it is
easily available). Do consider how the link and content growth patterns
for your sites may affect the engines’ perspectives on your rankings and
trustworthiness.
