Most Shopify marketing agencies charge based on retainers. Retainers are great for agencies as it smooths cashflow and means that even if your team ignore an account - they'll still get paid.
However, obviously they're not so great for the shopify store owner. Some agencies will work hard, and others won't.
Here are a few quick things that you can check to see if your agency is working hard enough on your account
One really great feature of Google Ads is that they track all the changes that agencies make inside the tool.
The change history shows you all the changes that different users have made in Google Ads. Clearly - if no one has made a change for a couple of months - it's time to look for a new agency.
Your change history should show regular changes. For larger accounts you'll see lots of changes most days. For smaller accounts - once a week or so is fine.
Most agencies will send you reports. However, the numbers alone don't tell the full story. What you want is also some detailed commentary too. You need to understand that they are thinking hard about how to improve your business. Not just doing the minimum to not get fired.
We follow a format that goes like this.
What has worked well
What could have worked better
What we're doing next
What results we expect
It doesn't take long - so won't waste time and it gives our clients a clear idea of our thinking. We send it through as an email that is written from scratch every time. So that we're not using templates and being lazy. We force ourselves to think.
Is your agency proactively coming up with ideas of what to try next? Are they following your social media to see what's working and what's not? Are they asking you for details about your future promotional plans and working collaboratively with your team to ensure that the work is nailed?
A sure sign that your agency is working hard is them asking for more creative. Whether images or copy - when you're growing an account you need a constant stream of new content to test. If they're not asking for it, they're not testing agressively enough.
I'm a massive fan of phone calls. There is nothing better for ensuring that there is excellent mojo in the team (both yours and agency side) than a phone call. You'll want to do regular calls, however I also recommend calling them out of the blue. You can ask them questions and check that they actually remember who you are.
Hope these tips help.