Methods for recognizing strings, labeling the strings with a semantic category and providing e-commerce actions based on the category is disclosed. The semantic category may include a type label and other metadata. Recognizer plug-ins perform the recognition of particular strings in an electronic document. The recognizer plug-ins may be packaged with an application program module or they may be written by third parties to recognize particular strings that are of interest. Action plug-ins provide possible actions to be presented to the user based upon the type label associated with the string. Tradenames, trademarks, formal names or types of consumer products may be labeled and actions to buy the products may be presented. The metadata may be used to implement coupon and affiliate programs to reward frequent shoppers or frequent recommenders. Numerous other e-commerce opportunities are presented via the semantic category and the metadata.