My mobile service provider recently decided to push down a "value-added" service, for which they sent out an <ADV> SMS to inform that they have automatically opted me in for the 1-month trial promotion. The service is free during this 1-month trial, but will incur monthly charges thereafter. If I decide not to continue the service, I need to dial back or go online to opt out before the 1-month period expires.
So if I did not read the SMS fully, and fail to follow up to opt out, I would end up paying monthly charges for a service that I never requested.
Incidentally, the 1-month period expires on Christmas day, and they would send me another SMS on that day to inform that the service becomes chargeable from then on. Interesting Christmas gift for them to give me
