It's interesting to consider what happens to the sunbathers! In the article, sunbathers are treated as a passive, uniformly distributed part of this game-theor

It's interesting to consider what happens to the sunbathers! In the article, sunbathers are treated as a passive, uniformly distributed part of this game-theoretic setup. If the sunbathers are active participants, however, the game changes. Once the vendors move to the center, sunbathers will too (except for those that value privacy, quiet, etc. more than ice cream (!?)). Suppose that this "tourist clustering" effect has taken hold, and now some new vendors set up shop. They have very little incentive to set up anywhere except the middle. Gradually, you get a cluster of largely indistinguishable ice cream vendors, all vying for the custom of a large group of tourists... ...and you've effectively arrived at a beachside ice cream market where advertising is essential for success. (You've also potentially created a market to sell a more "authentic" ice cream experience to sunbathers who would prefer to avoid the tourist cluster at all costs, so that as the ice cream vendors in the middle consolidate another vendor can come along and set themselves up as the "alternative" choice.)