When a marketing template goes out to a large audience, Meta can hold back part of the delivery and serve an initial slice first. Early engagement signals, such as reads, replies, blocks, and reports, decide what happens next.
If the early reaction is healthy, delivery continues to the full audience. If negative feedback is high, the template can be paused, and messages held during the evaluation are dropped rather than delivered late.
Pacing rewards the same habits as every other quality mechanism on the platform: a clean, opted-in list, a strong first line, and relevant targeting, so the first wave of recipients votes in the campaign's favor.
