Most CAD vendors now offer a free version of their software -- usually some sort of subset, such as just 2D or reduced-function 3D. And not just limited to 30 days of operation.
Offering a free version is a brilliant way to counter pirate versions. Why pay $1.60 for software (that might not work on your computer) when you can get a similar version free?
A problem with offering free software is that the CAD vendor has little idea of its success. If you're like me, you'll download the freebee, maybe install it, and check it out for all of five minutes. (One reason I don't spend much time with the free CAD downloads is that I have too little time to spend learning them.)
CAD vendors like to trumpet the download number, because it's the biggest number that can be used. But with annoying people like me who download but not use, the download number is pointless.
think3 created a community around its free 2D software, free2design. (I had completely forgotten about free2design until the name popped up on another blog today.) The site reports these numbers:
15,789 = Registered members
72,708 = Downloads to date
1,138,817 = Website visitors
Because someone actually using the free download is more likely to register to get support, the Registered Members number is a very useful indicator.
Even more useful is the ratio provided by think3's data: about 20% of downloaders use the software.