no proof, but according to this websites own data there are over 500,000 members, 200,000 currently active (and these are old numbers)... EF made only 7 million last year which works out to around 15,000 sales of Poser 7.  Now being generous lets assume that at least 60% of those buyers had never purchased Poser before... that means 9,000 new users.  Now lets be even more generous and assume that 60% of those new users have even heard of Renderosity and are active members in here that's 5,400 registered Poser 7 users out of 200,000 active, 500,000 total.   

Poser 6 was a dissapointment, was quickly replaced by P7 and debuted head to head against D|S's initial launch... I doubt it sold nearly as well as Poser 7 has and most probably upgraded to P7 pretty quickly.  Probably around 3,500 registered P6 users are in here and still active.

Poser 5 did well and was briefly given away for free... I'd assume at least 10,000 registered and active Poser users are in here that haven't upgraded.  P5 probably has the most users of any active Poser group.

Poser 4 & Poser Pro are most likely making up the vast majority of inactive users as most people that bought those versions and are still active have most likely upgraded as well.  Being generous lets give this group 10,000 as well.

That's around a total of 28,900 active & legit users out of 200,000+ active, 500,000 total.  I was wrong I guess, only around 85% are illegitimate, not 90%.  Oops, sorry.  My bad.