Regarding how journals get ranked, increasingly what is involved
is some kind of citation measure, not some survey of "prestige"
or "use."  There are indeed lots of complications with this, with
the ones that generate "the usual suspects" at the top using some
kind of method that weights more heavily the citations in journals
that themselves are getting more cited in the original base list.

One gets very different rankings if one uses different methods
or different bases.  Thus, simply ranking by raw, aggregate citations
gives quite a different list, with the usual suspects somewhat further
down, and journals that are more multidisciplinary, sometimes not
very orthodox, e.g. Ecological Economics, doing much better.

I would agree in any case with Deirdre that when people are being
evaluated professionally their actual work should itself be read and
evaluated on its own merits, irrespective of where it was published.
(Although, of course, one can get into the business of looking at
citatiions of someone's work in particular, rather than the citation
rates of the journals in which the work has appeared.)

Barkley Rosser