The web is replete with marketing driven free stuff. Usually, these promotions require personal information or the completion of "program requirements". "Program requirements" is the term used when a promoter desires for you to buy 1 or more items from a couple of categories. After the "program requirements" are complete the company sends you the free stuff. The promoters frequently offer more gifts after you get friends involved.
Finding out more
To find more information on any given program's requirements all of them ask for some up-front info. Usually the information is something minor like a telephone number. I've signed up for several previously without getting any spam so I guess that this information is used to validate you are a real person or that you live in a qualifying region.
Usually these offers have program requirements that include a minor category where, for example, you take a survey - no purchase required. The medium category will require a modest purchase, for example, a music service membership for a couple of months. Beyond this the promotional requirements get specific to the marketer and can vary a lot.
Program Fullfillment
Since the offers that ask for little more than personal info are obvious we will focus exclusively on the promotional gifts that have program requirements. As stated before the program requirements involve a few categories of widgets that must be bought. The purchases must be made in a certain time period.
Obviously the free stuff is worth while when the services for purchase are widgets you already want. Because the promoters provide as wide a variety of categories and items as possible to appeal to as many buyers as possible. The promoters understand that these offers only make sense if you want what they have to offer.
Get them before they are gone
These promotions are worth checking out. The entry fee is minor - an email address or telephone number. Then check out the requirements. I wouldn't provide a credit card number except to purchase from reputable companies.