16. A system for providing keyword-based services to a user recipient of a message on a mobile device, the mobile device having a processor for executing computer-executable instructions, the system comprising: a memory storing computer-executable instructions of: a market segment component configured to determine a market segment of the user based on observed user activity on the mobile device and further based on profiling messages received by the user; an identification component configured to identify a plurality of keywords in a received text message by comparing text in the text message with the contents of a keyword inventory that is maintained on the mobile device; a filtering component configured to select a subset of keywords from the identified plurality of keywords, the filtering component selecting the subset of keywords based at least in part on user-specific information, including the market segment of the user, that is maintained on the mobile device, each of the subset of keywords having an associated one or more advertisements and contextual services; a display component configured to display the received text message to the user and to display one or more advertisements and contextual services associated with a keyword when a user selects one of the subset of keywords in the received text message; and a communication component configured to receive a selection of a keyword and an associated advertisement or contextual service by a user, the communication component invoking the advertisement or contextual service to obtain additional information associated with the selected keyword for display to the user, wherein invoking the selected advertisement or contextual service comprises transmitting the user-specific information to the selected advertisement or contextual service provided that the user has authorized such transmittal.
18. The system of claim 16 , wherein the market segment of the user is further based on information received from a service provider of the user.