Miss Call Services
Missed Call Service directs your callers to a short announcement that tells them they can leave a short message that will be sent as an MMS to you (the person that missed the call). The service captures and records for you all of the calls you have missed, then sends you an audio file as an MMS for you to listen to at your convenience. Even if your caller has their Caller ID blocked, they can still leave their number. Better still, if the caller wishes to leave an alternative number they can do this too. The enhanced missed call service is offered for free and is the default for customers that do not want voicemail. Missed calls are especially prominent in India.
Expanding upon their use as a communications method, they have been adopted as a form of marketing communications, in which users can "missed call" specific numbers and receive a call or text back that contains advertising and other content.
Other forms of services have also been built around the use of missed calls in such a manner, primarily to take advantage of the fact that feature phones are still relatively common in India as opposed to smartphones.