SPI has "non-contributing members" and "contributing members". Contributing members have access to statistics about SPI's membership. The page with these statistics includes 4 metrics: NC Applicants Pending Email Approval, NC Members, Contrib Membership Applications and Contrib Members. A description of these metrics was provided by Jonathan McDowell in http://lists.spi-inc.org/pipermail/spi-general/2016-July/003467.html
This page is not accessible to the public at this time. While I hope the status of membership could be much more transparent, making these statistics public would be a good and easy first step. I am hereby asking to make the existing metrics available to anyone.
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Filipus Klutiero
http://www.philippecloutier.com