I'm not sure what you mean by "appropriately" here. But
for a lot of people, "appropriate" means getting listed
prominantly, first if possible, but certainly in the first
page of hits returned by the search engine. We can agree
to disagree on whether such a thing is ethical, but I think
we would both agree that as long as people think they will
benefit from listing a given keyword 40 times or creating
multiple "search-engine advertisement pages" that all point
to the "user-browser advertisment page", they will do it.
I don't think the guidelines you listed are adequate for
preventing people from search-engine spamming.
Nothing in the guidelines you listed suggested either 1) how
somebody might get themselves listed first, or 2) that listing
a given keyword 40 times or other such behaviour deemed
unethical by a lot of people on this list will not help you
get listed first.
By the way, I agree in general that search-engine spamming
does not serve the common good, and so we should seriously
find ways to discourage its use.
There are perhaps a number of approaches to doing this.
Trying to build robots that are smarter than the spammers,
and that "punish" them by not listing their pages at all,
is I think not a good approach in the long run. It just
leads to escalation of smarter and smarter spammers and
robots.
As I try to think through this, though, I'm not finding
much in the way of good and easy solutions.
What I personally would like to see is a well-known keyword
vocabularly that allows people to use search-engines as a
kind of yellow-pages. For instance, say there was a key-word
like "keyword:search-engine:yellow-page". Say further that
when such a keyword was used in a search, the search engine
would make an attempt to display only one page per "business"
(though it is not clear to me how to do this), and further,
that the search engines would agree to always randomly list the
matches (and make it clear that this is what they are doing).
There could be well-known keywords for denoting a geographical
area, if this is pertinant to the business, plus perhaps
well-known keywords for describing types of businesses, though
I understand that standardized terminology is a double-edged
sword.
Something like this might result in an environment where 1) it
in fact doesn't pay to spam, and 2) it is clear to everybody
that it doesn't pay to spam.
PF