PPC Investigator - Troubleshooting
Geetanjali Tyagi avatar
Written by Geetanjali Tyagi
Updated over a week ago

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Why is there a discrepancy in the Search Query Volume metric when I compare it year-to-year?

We don't recommend doing a comparison between the "last year" and "this year" periods, as the search query volume is not necessarily equal for both periods.

For example, there were 4 campaigns last year that accrued 1,000 impressions and which were losing around 10% impression share. This means that they were potentially losing around 100 impressions.

In this year, let's say there are 8 campaigns that accrued around 2,000 impressions and are losing the same 10% impression share which is a loss of 200 impressions, in this case.

The comparison of these values is not in equal weights and therefore the resultant value of search query volume may not be the correct number.

Pro Tip: When comparing Search Query Volume between different periods, make sure you do so when the number of campaigns remains constant, and not when the number of campaigns changes.

You can read how Search Query Volume is calculated here.

Why do I see a discrepancy between the Cause Chart and Root Cause Analysis?

This can happen if an Express campaign is part of the selection. While the Cause Chart is able to aggregate the data for the selected campaigns, the Root Cause Analysis identifies the top movers for the selected campaigns. It then calculates the difference based on each element in the positive and negative top movers list.

Since the API doesn't return performance data at such a granular level (for Express campaigns), the discrepancy is expected.

Why do I see a discrepancy in Google Ads' Cost per Conversion Calculations?

While calculating, Google ignores some spend that happened on some old mobile phones, as they consider them "ineligible clicks". Considering this information, the right way to calculate the cost/conversion is to take the total cost and divide it by the number of conversions. Optmyzr tools work with this way of calculation.

You can read more about it here.

Why are the Impression Share metrics for Search and Display greyed out on PMax campaigns?

PMax campaigns do not use the standard Search or Display networks; they use the cross-network type to show your ads. Unfortunately, Google Ads doesn't support Impression share data at the cross-network level, and therefore, you don't see the data in Optmyzr as well.

I see a discrepancy in PMax campaigns, where when I select "all campaigns," some metrics have a value of X, but when I only select PMax campaigns, these metrics have the value greyed out.

There is currently a discrepancy from the Google Ads API for PMax campaigns. By default, the API doesn't provide the Impression share-related metrics for the PMax campaigns, but at the account level, it considers the impressions of PMax campaigns too for calculating the account-level Impression Share.

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