A mobile device (10) subscribes to receive messages targeted to a first geographical area (18-A), e.g., a first tile or area of a grid for geocasting. The mobile device (10) also subscribes to receive messages targeted to a second geographical area (18-B), e.g., a second tile or area of the grid for geocasting. The mobile device (10) notably does this such that the mobile device (10) is simultaneously subscribed to receive messages targeted to the first geographical area (18-A) and to receive messages targeted to the second geographical area (18-B).