Restructure when
- Brand and non-brand are mixed and cannot be separated any other way.
- Budget cannot follow profit because everything lives in one campaign.
- Conversion actions were wrong, so all historical learning is built on the wrong signal.
- The structure cannot carry the budget you now want to spend.
Do not restructure when
- One month was bad.
- A new agency wants to show activity.
- The real problem is the feed, the offer or the margin.
The cost
Two to four weeks of unreliable numbers while Google relearns. Plan for it, tell the client, and do not do it in November.