Tenlinks today Reported that Autodesk has announced it has sold it's 800,000th seat of Inventor since introducing the product nine years ago. Impressive? Definately, but consider the fact that at the time they launched, they had a HUGE Autocad user base to advertise their new software too.
How many seats of Solidworks are out there? Thats been an unadvertised number for a couple of years. The last official publicly announced number was 450,000 which was announced at Solidworks World in Las Vegas, back in 2006. The number I have heard floating around in the past 3 months is that Solidworks has in the area of 750,000 seats out there.