“Pizza’s here!”

That’s how you should start your next meeting, according to Jeff Bezos, CEO of Amazon.

When considering how many employees should come, Bezos has a strict “Two Pizza Rule”—in other words, if everyone wouldn’t get a couple slices of pie, too many people are coming.

The theory is that whittling down a meeting’s attendees to the most essential is vital for productivity. In Bezos’ case, that means the invite list usually hovers between five and eight.

Of course, capping a meeting at eight won’t work for every organization or type of meeting. The Two Pizza Rule is ideal for, say, brainstorming and problem-solving sessions, where quality is vastly more important than quantity. It’s also great to keep in mind when holding decision-making meetings, because when trying to reach an agreement, it’s easy to have a too-many-cooks situation.

Conversely, one-way info-sharing meeting should be attended by anyone for which the information is relevant. For example, an update on the company’s progress and future goals should definitely include the whole company. Similarly, if you’re trying to figure out a multi-department strategy, a representative from every department should be there—even if it means ordering an extra pie or two.

In any case, though, a rule like Bezos’ is a good one because it forces you to reevaluate your meeting policies. Far too many meetings are unproductive because of their inflated invite lists. But if you think through the guest list ahead of time and make sure you can justify each person’s reason for attendance, your meetings will be transformed. Productivity guaranteed.

Photo of pizzas courtesy of Shutterstock.