Walker Digital [NPE] filed three separate suits against Amazon, Barnes & Noble, and Expedia, alleging that the defendants’ websites infringe a patent related to pre-sale product substitution suggestions.  The patent-in-suit was issued on February 7, 2012, the same day these suits were filed.  Walker Digital, which formed a strategic partnership with IP Navigation in January 2011, holds over 500 issued and pending patents.  Since October 2009, Walker Digital has filed over 30 patent infringement suits against more than 150 unique defendants.  In July 2011, Bloomberg reported that Apple and Groupon settled with Walker Digital for $25 million combined over patents related to online commerce and marketing.  2/7, District of Delaware, 1:2012cv00140; 1:2012cv00141; 1:2012cv00142.