Why did this change? Splitting a change, and "Why?" on rows

1. Why did this change?

On any report with a period (say last 30 days), press Why did this change?. It compares this period with the one before and splits the change by each of the source's fields (channel, campaign, flow, form, source and so on), biggest contributor first. For rates it also says whether the change is mostly mix (more of some groups, less of others) or the groups themselves changing.

2. Read it as "moved with"

A split shows where a change sits, not what caused it. Where a campaign or flow has a holdout that measured lift, it says so.

3. Why? on a row

Why? on a timeline email, a campaign's recipient, a segment member or an agent's ledger row explains what produced it from what was recorded: the campaign and its lists, the flow, its filter and the event that started it, the rule condition by condition with the person's values, or the agent's job.