+2 votes

For example a graph like this of the CPA:



What would be the steps you'll take to understand what is the reason for this? what steps would you then take to resolve this? what would you look at?

by (440 points)

2 Answers

+2 votes
When helping others on Facebook Ads, I often hear "performance is worse" in general terms, which often is meants as "CPA or ROAS is doing down". This is just the overall outcome and it can have many different reasons, so you want to narrow down the hypothesis.

The first step I take in this case is to split the funnel in parts and identify if the degradation happened:
- From impression to installs : looking at top funnel metrics (IPM, CTR, IR) and prices (CPM, CPI). Could be a sign of underperforming new creatives, audience saturation, creative fatigue, audience size changes, ASO changes, seasonality, or many other factors. If you have that problem check ad distribution over time, frequency etc
- After the install, looking at bottom funnel metrics (install to "action" rate and the steps leading towards it such as signup rate, tutorial completion etc). This could be the result of new product experience, cohort not fully formed & matured (last days can often be shaky), a change in the audience (have you expanded/broadened targeting? - or maybe FB is showing your ads to different kind of users). You may want to look into your own analytics, as well as checking a similar cohort (OS/country) from other sources of traffic: is this specific to Facebook and that campaign, or affecting all traffic in this segment?

Worst case scenario it can be both things at the same time.

2 more things you want to check as CPA/ROAS change radically: did spend volume change a lot? and what are recent changes that were done in this particular campaign/adset.

The idea behind running those different checks is to understand what part is changing and which is not, so as to focus your efforts instead of having only the overall outcome. Your CPA/ROAS
Expert in Facebook by (2.5k points)
+1 vote
It seems that the ad set was in the learning phase for more than 14 days, which isn't optimal. I would check if the reason is the daily budget or audience limit.

In this specific case if all other campaigns behave the same way as they were I would say that the creative you added or the audience you updated led to the CPA increase. I would roll out the audience and the new creative.
Expert in Facebook by (1k points)