This is the data I observed the day before yesterday in one of my campaigns. $160 per lead while the target CPA of groups in it is from $8 to $18. Way too high! So, here is my protocol for reacting to such situations.

1) Check if the landing pages are working properly.

2) Check if tracking is working properly.

3) If both are fine, then check also: were there any considerable fluctuations in matched targeting options, such as search queries or placements?

4) If all of the above are fine, then look at a wider date range. The last 7 days, last 14 days, last 30 days (the fewer conversions you have, the wider date range you need to look at). Are fact CPAs considerably higher than target CPAs?

If yes – you need to dig deeper. The most probable reason is that you don’t have enough conversions for AI to optimize well. So, the problem isn’t yesterday’s fact CPA but your setup in general.

If your fact CPAs during the last 7 days, last 14 days, or even last 30 days are close to your target CPAs, then it’s just a normal fluctuation of CPA. Plus, you need to factor in the lag between the click and conversion. Even if the conversion event is a lead, not all of them occur within the same day.

Here is how stats for this campaign look:

• Last 7 days – much closer to what I want it to be
• Last 14 days – fact CPA is very close to target CPA.
• And, as of today, more conversions occurred from clicks from that day before yesterday.

Conclusions

• CPA fluctuates on a day-to-day basis -it’s normal.
  • If your fact CPA is much higher than your target CPA – take the steps listed above.
  • If your fact CPA is much lower than your target CPA – don’t expect it to be this way in the future 🙂 The AI will compensate it with a higher CPA later, so your average CPA is closer to your target CPA.
• You need to factor in click to conversion lag