Named after the first person to describe them, American economist and game theorist Thomas Schelling a Schelling point is a default point that people gravitate toward in the absence of clear direction.
More generally, a Schelling point is a solution that people tend to use in absence of full knowledge or clear communication on a matter. While the classic example of trying to meet a friend in a large city involves physical points (the St. Louis Arch, the Empire State Building), or points in time (12:00), Schelling points are perhaps most useful in game theory, which usually focuses on more abstract coordination problems.
Schelling points are pervasive in society; for example, when meeting a new person we may have no idea what might be a productive topic of conversation, but many people will start with the weather, and may refine their conversation based on gender to target sports or fashion. Likewise, news agencies do not know what will be the next news story to capture the public's attention (Cecil the lion was not an obvious choice, for example), but celebrities and politicians are usually good bets. These are clear examples of one of the key factors in developing Schelling points; points that work get reinforced by both parties, without specific planning or even desire. While you may not be thinking about that Big Popstar, a news story about her is interesting enough that you will register it... while a story about Dave Calhoun may not trigger any interest at all. The journalists may not see any social value in reporting on Big Popstar, but that's what people read, so that's what they report on next time.
There are, arguably, some Schelling points that are culture independent; any culture might be likely to be drawn towards truth, or perhaps alternatively, to extraordinary claims. When trying to send a message that can be read by aliens, we tend to start with math, in hopes that any technologically advanced species will see that this is an obvious starting point. And in humans we have some attractors that are good bets across cultures; if you want to make friends, come bearing gifts and break bread together -- rules that work for international diplomacy, traveling overseas, or just going on a date.