23. The apparatus of claim 18 , wherein the action promotes e-commerce.
18. Apparatus comprising: a) at least one processor; and b) at least one storage device storing processor-executable instructions which, when executed by a processor, perform a method of associating an electronic document work with an action, the document work comprising text, the method comprising: 1) electronically extracting within a client device features from the electronic document work; 2) transmitting the extracted features from the client device to one or more servers; 3) receiving at the client device from the one or more servers an identification of the electronic document work based on the extracted features, wherein the identification is based on a sub-linear search to identify at least a neighbor; 4) electronically determining an action based on the identification of the electronic document work; and 5) electronically performing the action on the client device.