You have to provide your address and zipcode and then load e-centives' software to get the coupon. According to e-Centives' website:
Will I receive e-mail?
Every week E-centives scours the Web to find the best deals online and delivers them right to your inbox in one convenient e-mail. You can indicate which e-mail format you prefer (HTML -or- Plain Text) and if you would like to occasionally receive exclusive offers tailored to your shopping interests from E-centives.
So if you're going to sign up, use a disposable address to sign up, and be sure to uncheck the toys-r-us spam email box. By the way: they also leave tracking cookies behind.