A flexible, extensible, and dynamically configurable message service gateway that offers inter alia a façade through which a Content Provider (CP), among others, may invoke services to simply and easily complete among other things opt-in and opt-out activities in connection with a CP campaign or initiative. Among other things such a façade may hide various of the complexities, technical aspects, etc. of different communication paradigms including for example Short Message Service, Multimedia Message Service, Internet Protocol Multimedia Subsystem, Wireless Application Protocol, Electronic Mail, Instant Messaging, Unstructured Supplementary Service Data, etc. Such a façade may be offered by a centrally-located, full-featured Messaging Inter-Carrier Vendor.