Friday Mailing: Amazon Advertising's Seismic (?) Breakout Quarter

Amazon broke out its Advertising business from "Other" in its earnings release for Q4 2021 yesterday. At $31.2B it's an enormous business, as Axios' Sara Fischer highlighted this morning: it's one of the fastest growing advertising businesses in the world and now generates more annual advertising revenue than Microsoft, Snapchat and Twitter combined.

We …