Abstract: The provision of a viewing incentive comprises determining a set of unique identifiers (13). The identifiers (13) may be generated for this purpose or a set of pre-existing unique identifiers, such as telephone numbers, customer reference numbers etc. A selected identifier (19) is presented in conjunction with a programme, advertisements (18) or other promotional material, e.g. superimposed over, or presented in its own right during a commercial break or other break in programme content. If an identifier (13) held by a viewer matches the selected identifier (19), a reward is allocated to the viewer. Alternatively, non-unique elements (25) forming part of the identifiers (13) may be presented and a viewer holding an identifier comprising a predetermined number of said elements (25) may be allocated a reward. In another arrangement, a question may be presented and a viewer submitting a correct answer may be allocated a reward. The identifiers (13) can be reused in further commercial breaks/programmes.