From a business point of view, you might have to give up some demographic data in return for the valuable information on offer. For instance, one of the Web sites I manage is particularly attractive to human resource professionals. We've commissioned a series of White Papers that we'll give to you in return for you telling us who you are and if you are going to be in the market for any of our products in the future. Even if you're not, you still get the White Paper and we sincerely hope people will find it useful. We also hope people will remember us when it's time to upgrade or replace their software.
Free trials are limited-time demo versions of commercial software.
You have 30 days from the day you install these programs before it's time to either buy them or uninstall. Shareware is a similar model but generally comes from smaller software developers. Often their software will fulfill a niche that is overlooked by the Big Guys. Rather than shipping on a CD-ROM, the program is compact enough to download with a modem. Once you install a shareware program, you're supposed to pay for it after a certain number of days or it might stop working.