Should mobile app developers be worried about a fall-off in ad revenue? Maybe not.
VRTCAL published a three-part series of our impact studies to see how the iPhone Device ID change could affect our industry. Also known as the Apple Device ID or IDFA, our industry was gearing up for the release of Apple’s iOS 14. Thankfully, Apple delayed their release. Below are our three parts of the iOS IDFA impact studies. And toward the end, we compared our results from the impact study to a similar impact on Android GAID. We hope you find the study meaningful and informative.

Will iOS 14 impact your app display brand advertising revenues?
VRTCAL performed an impact study for the future release of iOS 14, which will add restraints to utilize IDFA (Identifier for Advertisers). For all three impact studies, we wanted to see how IDFA impacts advertising revenues.

For this 1st impact study, we implemented the following test parameters:

Display brand advertising CPM ad units.
Ad sizes: 300x250s, 320x50s, 320x480s.
Geo: US only.
Programmatic demand only, no PMPs with specific targeting.
Random samples during a typical mid-weekday.
Platform-wide, no app type or genre was targeted.
We found the following results.

iOS display ad requests were:

52% with IDFA.
48% without IDFA.
Of the display impressions delivered, they were:

57% for those with IDFA.
43% for those without IDFA.
Ad requests without IDFA had a fill rate that was 18.6% lower than those with IDFA.

Analysis:

We analyzed this data from this first impact study and concluded the following:

We found it surprising that 48% of the ad requests had no IDFA. That was higher than expected.
We also were surprised that there was only an 18.6% drop in programmatic brand advertising fill rates, which was much less than expected.
If IDFA utilization drops to 10% permitted versus 90% not permitted, there would be an 8.5% or so decrease in impressions.
How will new IDFA restraints affect ad performance?
In our 2nd impact study, we dove deeper into specifics while mindful of specific concerns voiced by our clients.

For this second impact study, we implemented the same test parameters:

Display brand advertising CPM ad units.
Ad sizes: 300x250s, 320x50s, 320x480s.
Geo: US only.
Programmatic demand only, no Private Marketplaces (PMPs) with specific targeting.
Random samples during a typical mid-week day.
Platform-wide, no app type or genre was targeted.
We discovered the following results:

iOS display ad requests were:

52% with IDFA.
48% without IDFA.
Of the display impressions delivered, they were:

57% for those with IDFA.
43% for those without IDFA.
Ad requests without IDFA had a fill rate that was 18.6% lower than those with IDFA.

Analysis:

We analyzed this data from this first impact study and concluded the following:

We found it surprising that 48% of the ad requests had no IDFA. That was higher than expected.
We also were surprised that there was only an 18.6% drop in programmatic brand advertising fill rates, which was much less than expected.
If IDFA utilization drops to 10% permitted versus 90% not permitted, there would be an 8.5% or so decrease in impressions.
How will new IDFA restraints affect ad performance?
In our 2nd impact study, we dove deeper into specifics while mindful of specific concerns voiced by our clients.

For this second impact study, we implemented the same test parameters:

Display brand advertising CPM ad units.
Ad sizes: 300x250s, 320x50s, 320x480s.
Geo: US only.
Programmatic demand only, no Private Marketplaces (PMPs) with specific targeting.
Random samples during a typical mid-week day.
Platform-wide, no app type or genre was targeted.
We discovered the following results:

Ad requests:
320x50s
With IDFA – 46.1%
Without IDFA – 53.9%
300x250s
With IDFA – 63.7%
Without IDFA – 36.3%
320x480s
With IDFA – 57.4%
Without IDFA – 42.6%
Non-Gaming
With IDFA – 44.5%
Without IDFA – 55.5%
Gaming
With IDFA – 65.9%
Without IDFA – 34.1%
CPMs delivered:
Non-Gaming – The average CPM for those without IDFA was 33.2% of those with IDFA.
Gaming – The average CPM for those without IDFA was 65.4% of those with IDFA.
Analysis:
We analyzed this data from this second impact study and concluded the following:

The larger ad sizes (300x250s & 320x480s) had a higher percentage of ad requests with IDFA versus without IDFA.
Non-Gaming apps had a higher percentage of ad requests without IDFA.
Non-Gaming apps had a bigger drop in CPMs when without IDFA.
Gaming apps had a higher percentage of ad requests with IDFA.
Gaming apps did not have as significant a drop in CPM for those ad requests without IDFA.
How will Android GAID be Affected by Comparison
VRTCAL performed a 3rd impact study for the future release of iOS 14, which will add restraints to utilize IDFA. This third study provides data on the Android GAID (Google Advertising ID). There are rumblings that advertisers will shift targeting from iOS to Android devices.

For this third impact study, we implemented the same test parameters:

Display brand advertising CPM ad units.
Ad sizes: 300x250s, 320x50s, 320x480s.
Geo: US only.
Programmatic demand only, no PMPs with specific targeting.
Random samples during a typical mid-weekday.
Platform-wide, no app type or genre was targeted.
We discovered the following results:

Ad requests:
320x50s –
With GAID – 66.3%
Without GAID – 33.7%
300x250s –
With GAID – 90.5%
Without GAID – 9.5%
320x480s –
With GAID – 95.4%
Without GAID – 4.6%
Non-Gaming –
With GAID – 85.4%
Without GAID – 14.6%
Gaming –
With GAID – 67.4%
Without GAID – 32.6%
CPMs delivered:
Non-Gaming – The average CPM for those without GAID was 33.5% of those with GAID.
Gaming – The average CPM for those without GAID was 45.4% of those with GAID.
Conclusions
Apple wants to protect user privacy on their devices. iOS version 14 advances the privacy initiative further along. While we expected to see a significant impact on display brand advertising revenue, we found to our pleasant surprise that maybe iOS 14 won’t have as big an impact as expected.

Then again, it appears that Apple has decided to delay it’s IDFA changes until early next year.

Is that reason to celebrate? Perhaps, but as your trusted ad partner we will be monitoring developments closely.

Further Reading
Tech Crunch, “Apple Won’t Force Users to Opt Out of Tracking Until Next Year”