When you have two TV sets at home and
you wish to watch a different channel
on each one of them at the same time.
Whether you already have O2 TV or you are just getting it, you can also buy the O2 TV Multi service. Your decision what to watch in the evening will be much easier then.
You can have only one O2 TV tariff and yet you can enjoy all channels on two TV sets. You just need to buy the add-on O2 TV Multi service with an O2 TV tariff and you need to have two set-top boxes.