A retainer can be a great way to work with an agency. It can also lock you into something that isn't working. Ask these questions before you sign.
1. What exactly will you do each month?
Get a list of deliverables or hours. "Ongoing optimisation" isn't a deliverable.
2. Who will do the work?
Ask for names and roles, and whether any of the work is outsourced.
3. How will you report, and what will you measure?
Agree on a small number of measures that relate to your goals, and how often you'll review them.
4. Who owns the accounts, files and content?
Ad accounts, analytics, domains, websites, designs and content should belong to you. Make sure the contract says so.
5. What's the minimum term and notice period?
Know how long you're committed and how to leave.
6. What happens if results aren't what we expected?
Ask how they handle underperformance. A good agency will talk about reviewing and adjusting, not just staying the course.
7. What isn't included?
Ad spend, software subscriptions, photography, printing and extra rounds of changes are common extras. Ask upfront.
A good sign
The best agencies welcome these questions. If an agency gets defensive, that tells you something too.