Extensive Introductions

Why does Rachel spend halve the show introducing the stories that are coming up next? Maybe use a couple of sentences as introduction and spend the rest of the time actually providing people with news?

I'm not very much used to tv having a 24-hour news channel, being from the Netherlands, but is it really necessary to just try to fill the time with nonsense and silly introductions, while you can just spend the time of giving real-time news from all over the world?