They host the Aspen Ideas festival which I'm guessing is often a big revenue driver. Many publications (the New Yorker for instance) have moved to hosting these events to diversify their revenue streams. Whoops.
A number of organizations that make a chunk of their operating income off events and have made them virtual still seem to be trying to collect possibly reduced but still hefty ticket prices. There's one event I was planning to attend in June that's now virtual and the $650 registration is a bar that I'm having a bit of trouble getting over.
And, yes, a number of magazines in recent years have added premium events to their revenue streams.