The official reflexive position among journalists regarding all things Upworthy is wry derision, and true to form, here was Felix Salmon's take on "attention minutes":

@elipariser You’re rewarding people who can turn the web into a lean-back, video-watching, couch-potato experience, just like TV. Yay. — felix salmon (@felixsalmon) February 6, 2014

"If I sit slack-jawed watching a video for 4 mins rather than 2 [minutes], that’s not 2X the amount of attention paid to the subject," Salmon continued on Twitter. "When people share Upworthy videos, they almost never write anything substantive about the issue, or the video."

The deeper lesson is that just about any conceivable metric will carry not only virtues and limitations, but also a certain seduction for digital media companies to corrupt it. Let's quickly review some...

Uniques: Unique visitors is a good metric, because it measures monthly readers, not just meaningless clicks. It's bad because it measures people rather than meaningful engagement. For example, Facebook viral hits now account for a large share of traffic at many sites. There are one-and-done nibblers on the Web and there are loyal readers. Monthly unique visitors can't tell you the difference.

Page Views: They're good because they measure clicks, which is an indication of engagement that unique visitors doesn't capture (e.g.: a blog with loyal readers will have a higher ratio of page views-to-visitors, since the same people keep coming back). They're bad for the same reason that they can be corrupted. A 25-page slideshow of the best cities for college graduates will have up to 25X more views than a one-page article with all the same information. The PV metric says the slideshow is 25X more valuable if ads are reloaded on each page of the slideshow. But that's ludicrous.

Time Spent/Attention Minutes: Page views and uniques tell you an important but incomplete fact: The article page loaded. It doesn't tell you what happens after the page loads. Did the reader click away? Did he stay for 20 minutes? Did he open the browser tab and never read the story? These would be nice things to know. And measures like attention minutes can begin to tell us. But, as Salmon points out, they still don't paint a complete picture. Watching a 5 minute video and deciding it was stupid seems less valuable than watching a one minute video that you share with friends and praise. Page views matter, and time spent matters, but reaction matters, too. This suggests two more metrics ...

Shares and Mentions: "Shares" (on Facebook, Twitter, LinkedIn, or Google+) ostensibly tell you something that neither PVs, nor uniques, nor attention minutes can tell you: They tell you that visitors aren't just visiting. They're taking action. But what sort of action? A bad column will get passed around on Twitter for a round of mockery. An embarrassing article can go viral on Facebook. Shares and mentions can communicate the magnitude of an article's attention, but they can't always tell you the direction of the share vector: Did people share it because they loved it, or because they loved hating it?