Amazon patents granted on 12 February 2013

4 US patents granted on 12 February 2013 and assigned to Amazon

1 8,375,305 Placement of user interface elements based on a window entry or exit point
2 8,374,922 Fulfillment network with customer-transparent costs
3 8,374,849 Multi-language relevance-based indexing and search
4 8,371,855 Sharing electronic books