Surveys using ‘Harvested’ e-mail lists
Harvested e-mail lists are sets of e-mail
addresses collected from postings on the
web and from individuals who are (wittingly
or unwittingly) solicited for their e-mail
addresses. There are many commercial entities
(‘e-mail brokers’) that sell lists of
e-mail addresses or access to lists of e-mail
addresses (just Google ‘buy e-mail list’).
Lists can also be assembled from resources
on the web. For example, lists of Yahoo
e-mail address holders by name or geographic
area can be created by anyone via the
Yahoo! People Search (http://email.people.
yahoo.com/py/). Similarly, World Email.com
(www.worldemail.com) has an e-mail search
feature by name.
However, it is important to note that
harvesting e-mail addresses and distributing
unsolicited e-mail related to surveys
could be a violation of professional ethical
standards and/or illegal. For example,
European Union Article 13(1) of the
Privacy and Electronic Communications
Directive prohibits the sending of unsolicited
commercial e-mail. In a similar vein,
the Council of American Survey Research
Organizations (CASRO) Code of Standards
and Ethics for Survey Research clearly
states that using harvested e-mail addresses
and sending unsolicited e-mail is unethical
(www.casro.org/codeofstandards.cfm). For a
more detailed discussion of the ethical
considerations and implications, see Eynon
et al., and Charlesworth (this volume), and
Krishnamurthy (2002) and the references
contained therein.
Samples derived from harvested e-mail
lists are non-probability samples because
they are based on a convenience sample
of e-mail addresses. For example, EmailMarketing Blitz (www.email-marketing-blitz.
com/customized_email_list.htm) says, ‘Our
targeted optin [sic] email lists are updated
monthly and gathered through special interest
websites, entertainment websites and special
alliances.’ Such samples should not be
confused with list-based probability samples
where the e-mail addresses in the list-based
sample represent a (virtually) complete list
of the e-mail addresses of some target
population.
The efficacy of sending unsolicited surveys
to a list of purchased or otherwise procured
list e-mail addresses is questionable. Not only
do e-mail addresses turn over quite frequently,
but many of those on the list may have been
recruited either without their knowledge, or
they may have inadvertently agreed by failing
to uncheck a box when they signed up for
something else. As a result, response rates are
likely to be extremely low.