Here is another example to try the Nash Equilibrium approach on. If they choose the same formats they will split the audience for that format equally, while if they choose different formats, each will get the total audience for that format.
Audience shares are proportionate to payoffs.
You should be able to verify that this is a non-constant sum game, and that there are no dominant strategy equilibria. But it doesn't matter which station chooses which format. It may seem that this makes little difference, since the total payoff is the same in both cases, namely 80 both are efficient, in that there is no larger total payoff than 80 There are multiple Nash Equilibria in which neither of these things is so, as we will see in some later examples. But even when they are both true, the multiplication of equilibria creates a danger. Actually, there is an even worse danger that each station might assume that the other station will choose CW, and each choose IM, splitting that market and leaving each with a market share of just 15.