Counterpoint: if you're going to run an all-hands with any kind of frequency, please ensure that virtually all the content is relevant to virtually all the attendees.

I spent many years at an (otherwise excellent) company that did quarterly all-hands meetings, which were de-facto sales events. The country manager (also the president of sales) went through the sales targets, then the sales pipeline, and then handed out awards to those involved in the biggest sales. Usually there followed some kind of presentation from engineering or marketing, with content meant to be useful to the sales staff.

For the people outside of sales there was a bit where other regional managers handed out awards, so at best there was something to look forward to and at worst it was a waste of time. But for the handful of us who also didn't report to one of those managers, the whole thing bordered on demoralizing.