Why would a manufacturer choose to offer samples through coolsaving rather than through another method such as in store sampling, for example?
If the site linked below is the one to which you refer, it requires your zip code and e-mail address. I'm sure if you enter your e-mail address, you'll be bombarded with advertisements for the site's products. That gives the manufacturer more opportunity to get his message to you.
http://www.coolsavings.com/Welcome.aspx?SessionID=f6e00589-9a17-4700-886b-f549a43e5c1f-1