Presumably there have been points at which you&#x27;ve said &quot;this space isn&#x27;t generating enough return any more, I&#x27;m going to stop advertising there&quot;. And while few businesses are set up in a way where it&#x27;s ever politic to say &quot;I think other departments could use part of this budget more effectively than mine&quot;, ultimately that kind of choice gets made one way or another.<p>You&#x27;re right that this is part of the normal cycle of capitalism, with all the creative destruction that entails. It&#x27;s quite normal for a new, growing industry to support a whole forest of new businesses, and then as the industry matures some of those will die off. But I think there&#x27;s one extraordinary thing here: the advertising industry is growing like a new market, the kind of market you see when the customer base is growing by 100% every year, like the early days of the Internet. But that growth simply isn&#x27;t there; advertising is by most measures a mature market. So what&#x27;s fueling all this expansion?