What is the difference between "contextual" advertising and
"information search"?  Is contextual advertising considered the same
as "information search" or is it somehow different?

Hi! Thanks for the question.

It seems that in marketing terms, the two concepts are very different.
In contextual advertising, the audience or viewer is being served up
by ads as he or she searches for information on the web. The
information being sought after could be about a product or could be
something very personal like info about a friend or data for a paper.
Nonetheless ads are served up in the hopes that the viewer will be
interested. It seems that in the present world this has been more used
in the internet.

Again in terms of marketing concepts, ?information search? meanwhile
is a process wherein the viewer is actively seeking knowledge or info
on a particular product or company. Unlike in contextual advertising
when the customer is most of the time passively being fed with
marketing ads, information, in ?information search? activities, the
customer is actively seeking knowledge whether online or offline about
a product he or she will buy.

I have found the following websites defining the characteristics of
?contextual advertising? and ?information search?.


------------------------------
Contextual Advertising:

?For me, contextual advertising is when ads are delivered based on the
content of a web page that's being viewed, usually in an automated or
semi-automated manner. In other words, the ad system sees that you are
viewing a page about travel, which it knows by having examined the
words on the page or other factors. The system then delivers up in
some fashion an ad that's related to travel. That's the "contextual"
part of all this. The ad about travel fits the "context" or subject of
the page.?

?Google Throws Hat Into The Contextual Advertising Ring?
http://searchenginewatch.com/sereport/article.php/2183531 


?A contextual ad system scans the text of a Web site for keywords and
returns ads to the Web page based on what the user is viewing, either
through ads placed on the page or pop-up ads. For example, if the user
is viewing a site about sports, and the site uses contextual
advertising, the user might see ads for sports-related companies, such
as memorabilia dealers or ticket sellers.?

?contextual advertising?
http://www.webopedia.com/TERM/C/contextual_advertising.html 


-------------------------------
Information Search:

?The process by which a buyer seeks to identify the most appropriate
supplier(s) once a need has been recognized. The information search
process may vary based upon variables such as organizational size and
buying situation.?

?Dictionary of Marketing Terms?
http://www.marketingpower.com/live/mg-dictionary-view1527.php 


Search terms used:
Contextual advertising
marketing glossary "information search"

I hope these links would help you in your research. Before rating this
answer, please ask for a clarification if you have a question or if
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Regards,                 
Easterangel-ga                 
Google Answers Researcher

Thank you for your quick and thorough work!