IDL and WAVE: # and types of users?

[Mitch Grunes <grunesm(at)sprynet.com>]

I wish to estimate how many users there are for IDL and PV-WAVE.

Anyone have any idea?  In terms of who has more, and in 
actual #'s?  Also: am I right that IDL users mostly fall
into the remote sensing community, while PV-WAVE users are
mostly financial business?  Or is that nonsense?

(I know I am a bit tired of trying to make my software work 
with both.)

My own best guess is that each has only a few thousand at the
very most.  But that would make it hard for them to make
a living--unless they make most of their income from software
subscriptions, technical help, training and consulting.