S&W is offering buyers of the new M&P guns(full-size or compact) two free magazines. However M&P Shield is not part of the promotion. This promotion runs from Nov. 14 to Dec 3, 2014
Forms can be claimed from
http://www.smith-wesson.com/webapp/wcs/stores/servlet/Category4_750001_750051_797653_-1_757992_757992_image
From: Smith & Wesson