At this point, almost everyone — online publishers and advertisers alike — agrees that raw pageviews are a poor measure of the value that a media outlet provides, but no one can figure out exactly what to replace them with. Some sites have chosen to focus on social sharing, while others are creating their own ways of measuring the actual time that a reader spends with a site’s content. Upworthy’s version of this metric is called “attention minutes,” and the company said Monday it has open-sourced the code so others can use it.

The need for a solid metric is fairly obvious: publishers of all kinds mostly rely on advertising, so they have to be able to show the brands, agencies and networks they deal with that they are reaching large numbers of the people they’re being paid to reach. The easiest ways to do that are pageviews and unique…