Thanks for your patience while I compiles the available information.
There is some formal and semi-formal research on the effectiveness of
vanity numbers, but there does not appear to be a great deal of
information available. I still feel the earlier link I provided --
though not really research oriented -- is still one of the better
documents available on this topic.
Nonetheless, I was able to pinpoint several studies and articles that
address your question head-on, and I have provided links to these --
and relevant excerpts -- below.
I trust this information will fully answer your question.
However, please don't rate this answer until you have everything you
need. If you would like any additional information, just post a
Request for Clarification to let me know how I can assist you further,
and I'm at your service.
All the best,
Study Conducted by Response Marketing Group Finds Consumers Retain
Vanity Numbers, Associate 'Toll-Free' With 800 Exchange
June 26, 2002
Vanity phone numbers recalled by 58% of consumers
Majority do notrecognize 888, 877, 866 exchanges as 'toll-free'
...The results show that vanity numbers (numbers that spell words,
like 800-NEW-SALES) offer significant advantages to advertisers. After
listening to a radio spot only one time, 58% of the subjects could
recall a vanity toll-free number. This compared favorably with
'hybrid' numbers (combinations like 800-639-HOME), which were recalled
by 44% of subjects, and especially numerics, which only 8% of
respondents could remember.
...The impact of particular toll-free exchanges on number retention
was also measured. While 58% of respondents could recall a vanity
number using the 800 exchange, numbers from the newer toll-free
exchanges - 888, 877, 866 - could be recalled by only 41% of the
subjects of the study.
Call Me Vain - toll-free vanity numbers
Nov 1, 2002
...Before committing to that perfect toll-free number, however, make
sure it's one with an 800 prefix. The study found that consumers are
41 percent more likely to correctly recall a vanity number with an 800
exchange than to remember a number preceded by one of the newer
toll-free prefixes, such as 888, 877 or 866.
[This is more of sales pitch than a research, but it had some
interesting perspective so I thought I'd include it]
VANITY NUMBERS, WHAT ARE THEY WORTH?
Toll-free Numbers on the Internet: FORTUNE 500 Companies
...Eighty-six percent of the companies on the FORTUNE 500 list use a
toll-free number, with 80% of them using a number with the 800 prefix.
Fifty percent of these FORTUNE 500SM companies have a vanity number.
Toll-free Numbers in Television Advertising
...Nearly a quarter of all television commercials use a toll-free
number as a response mechanism. The favorite is still the vanity 800
...Industries using toll-free numbers most often are real estate,
telecommunications, and lodging. Favored programming vehicles are game
shows, movies, and local news. Toll-free numbers are used most
frequently in 120 and 60 second commercials. Late Afternoon/Early
Evening is the top time slot. Internet address listings are also
1-800-Vanity Number on Radio Gets 14x More Calls Than a Numeric
...Vanity phone numbers dramatically increase advertising response
rates, according to a new study. The results of this study are
overwhelming evidence that vanity numbers are truly indispensable
...The results of this study, focusing on the use of toll-free numbers
in radio advertising, show that an advertisement using a toll-free
vanity number (a number that translates into words for easy recall)
yields 14 times more phone calls than an advertisement using a
toll-free numeric number.
[However, at least one observer has some doubts as to the merits of vanity numbers]
Vanity Numbers Have Drawbacks
The number 1-800-TAXHELP may look good on a business card, but the
concept of vanity telephone numbers has serious drawbacks for
professional services firms, according to one consultant... vanity
numbers "have their place, particularly in radio advertising. But I
believe their value is overrated." He adds that some studies have
shown that full-alpha[betical] 800 vanity numbers actually reduce
response rates. "They claim it's because people think they'll remember
the number, and thus put off calling until later," he says. "In
marketing, later often means never."...
Again, if there is anything else I can do for you, just let me know.
search strategy -- Google search on [ "vanity numbers" research ]. I
also searched a variety of newspaper databases, but these came up with
the same results already found through the Google search.