From Longman Business Dictionary
pigeonholepi·geon·hole1 /ˈpɪdʒənhəʊl-hoʊl/ verb [transitiveT] to consider a person, activity etc as belonging to a particular type or group, in a way that is too simple and therefore unfairSYN LABELElectronic books and multimedia had originally been pigeonholed as a small, exclusive market.