For France's Libération, Facebook Instant Articles drives a 30 percent increase in time spent

digiday reporting:
As an experiment, French political publisher Libération has spent the last two months publishing each of its 150 daily articles to Facebook Instant Articles. It turns out, people like reading articles there...
According to Facebook’s analytics, the time spent on articles has increased 33 percent to 4 minutes 40 seconds. Grangier ventures this could be because readers prefer the format of Instant Articles, or because pages load faster so they stick around for longer.
http://digiday.com/publishers/facebook-instant-articles-leads-30-percent-increase-time-spent-liberation/