Steve,
Self selection may be ideal, since developers and customers are also self
selected. If those who attended meetings in the past are no longer
involved enough to follow this list, it's very hard to see why their
opinions should count for more than those who are here now, actively
evaluating and working on PEM.
I'm not about to argue the problem of statistical inference. If you find
any two professional statisticians who agree on the population size for
which this sample justifies a confidence level of, say, 0.7, please let
us know.
I've received yet another response with Privacy as the top choice.
Doug