1. REST Hooks are 66 times more efficient than traditional polling.

Case study: Zapier is a SaaS which connects hundreds of other web apps together. Polling is a necessity because it is the most ubiquitous way to detect changes.

Over a representative time period, Zapier polled for changes 30 million times but only took action on 460,000 of those polls (1.5% efficient).

Contrast this with REST Hooks, where 547,000 hooks were received over the same period and all of them were acted upon (100% efficient).

In other words, if everyone implemented REST Hooks, server load for both the sender and receiver could be reduced by 66x.