The Win a $1000 amazon gift card page is shown through advertisements that redirect you to sites that display this alert. These advertisements can be displayed by installed adware programs or through less than reputable sites that are displaying them to generate advertising revenue.
For the most part, if you see a web page, then you can simply close the browser and start it again. On the other hand, if you are continuously seeing scams with alerts like “Win a $1000 amazon gift card”, then you should scan your computer for adware and remove anything that is found.
The “Win a $1000 amazon gift card” page is an web browser advertisement that asks if you shop at Amazon, and if you click on Yes, prompts you to enter your contact information. As it is not known what your contact information will be used for, it is strongly suggested that you do not enter it.