When we ship new versions of Firefox we do our best to avoid introducing new bugs or crashes, especially those that affect large numbers of users. One of the strategies we use to accomplish this is to ship new versions to a subset of people before shipping to everyone. We call this a "throttled rollout", and it's something we've been doing for many years. The tricky part of this is getting the new version to enough users to have a representative sample size without overshooting our target. Ou...
