It's a dark art, selling video games.
Players want to be teased with details of what they'll be playing, without spoiling any surprises. Trailers should contain a taste of the action, a flavour of the mayhem in stall - and apparently a supermodel.
Mercifully, the latest trailer for Call of Duty: Black Ops III employs the skills of Cara Delevingne for all the right reasons. She's not wedged into nonsensical proceedings to act as pulse-raising eye candy like Emily Ratajkowski; she's there to kick ass and suggest that, yes, even women have an interest in the male-dominated world of multiplayer video games.
So if we could stop making video game trailers like this and stick to the above, that'd be great.
Call of Duty: Black Ops III arrives on 6 November for PlayStation 4, Xbox One and PC