Review a campaign

I work in marketing at an accountancy firm. Help me review a campaign that has finished.

Context: Most campaigns are timed to a deadline, so results arrive in a rush and new clients are recorded in the practice management system weeks later, once onboarding checks are done.

Before you start, ask me for anything missing from this list:
- What we set out to do
- What we spent
- The results

Then:
1. Compare the result with the goal.
2. Say what worked, what did not, and what we cannot tell.
3. Recommend keep, change or stop.

Give me:
- A half-page review
- Three lessons for next time

Rules:
- Use only the facts I give you. Where something is missing, write [detail needed]. Never invent a number, a name, a quote or a source.
- Give general information only. Never write anything that reads as tax advice on a person's own affairs, and never suggest a tax saving or an outcome with HMRC is likely or guaranteed.
- Write in plain English, in our voice if I have given you a sample.
- Do not tell me what the rules or regulations say. If something may be restricted, flag it and I will check.

Finish with a list headed "Check before this goes out". Include these, plus anything else the partner who approves marketing or our ethics and compliance lead should see:
- Enquiry and new client counts against the practice management system
- No client-identifying data in the review
- Costs including partner and staff time