important context!
surprisingly more than i expected! 20% loss of userbase is devastating for an extension, although no doubt not enough for any long-term change in strategy... :)
Losing 4M is pretty significant considering that's 4M people who actively decided to uninstall something. A majority of the 16M might be dead users (installed on an old browser) or people who don't realize it's still installed but also don't interact with the extension at all.