>there are copycats that don't do the testing, don't optimize for their niche of readers, and are probably losing both money and readers because of it.

I think this is much more common than sophisticated A/B testing.

At our publication, we were able to make the business case that the added pageviews from pagination didn't make much of an impact on the bottom-line. Because we generally run out of premium ad inventory each month anyway, most of the extra impressions were just for extremely low-revenue, Google-served remnant ads. Again, some publications thrive on volume, but it's a tough way to make money as CTR on Google ads is very low.

>If it didn't improve their revenues, they wouldn't be doing it.

The publishing industry has not always been about maximizing profits. The weird hybrid of advertising and reader-supported has created a different mentality in the business. There are plenty of things that publishers still do- like supporting foreign correspondents- that are driven more by the editorial side of than the business side.