An expired domain name may now be subject to a temporary penalty. This is important, because it implies
an additional delay before a site begins to rank well. In some cases Google will even refuse to index the
pages at all during that period, leaving a web site vulnerable to content theft. Content theft is discussed
at length in Chapter 5, “Duplicate Content.”
It is also likely that Google devalues any links that are acquired before the re-registration of the domain.
At the time of writing, other search engines do not appear to penalize previously expired domains.
Duplicate Content Penalty
Search engines attempt to avoid indexing multiple copies of the same content — duplicate content. Many
search engine optimization experts hypothesize that not only does a search engine not index such pages,
but it also penalizes a site for having the duplicated content.
This is a subject of much debate, but in any case, having duplicate content will not improve the rankings
of a site in any of the major search engines. Therefore, duplicate content should be avoided, and this book
devotes an entire chapter to the subject.
The Google Supplemental Index
This is not strictly a penalty in and of itself, but it may be the result of one. Google stores its crawled
search data in two indexes: the primary index and the
. The supplemental index
stores pages that are less important to Google for whatever reason. Results from the supplemental
index typically appear at the end of the results for a Google query (unless the query is very specific),
and the results are marked as supplemental results.
Figure 2-1 shows how a supplemental result is denoted in a Google search results page. Factors that lead
to inclusion of that link in the supplemental index rather than the primary index are the lack of signifi-
cant unique content or a lack of inbound links to the said content. It may also be as a result of explicit
Chapter 2: A Primer in Basic SEO
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