CPA (Tap)

How CPA (Tap) is calculated

CPA (Tap) = spend ÷ tap-through installs. A tap-through install is a new download or redownload that Apple Ads attributes to a tap on your ad. Say a keyword spent $240 in a week and 48 installs followed taps on its ad: $240 ÷ 48 = $5.00 CPA (Tap). The numbers are hypothetical; the arithmetic is Apple's definition.

The same figure comes out of two other Apple Ads metrics: average CPT (spend ÷ taps) divided by conversion rate (tap-through installs ÷ taps). A $0.80 tap that turns into an install 16% of the time costs $5.00 per install. The split shows which side to work on: the price of a tap, or how many taps become installs.

How to use CPA (Tap)

• Set it against what an install brings in. If the installs from a keyword earn more over time than its CPA (Tap), the keyword pays for itself; if they earn less, lower the bid or pause the keyword.
• Compare keywords inside one country. A tap costs a different amount in each storefront, so a $5 CPA (Tap) can be cheap in one country and expensive in another.
• Read it on enough installs. On a keyword with a handful of installs, one more or one fewer moves the figure by a quarter or more; judge small keywords over a longer date range.

Storelift's Apple Ads screens use the same name, CPA (Tap), for this column.

CPA (Tap) vs CPA (Total)

CPA (Total) divides the same spend by all installs, adding view-through installs: people who saw the ad, did not tap it, and installed the app later. With more installs below the line, CPA (Total) is always equal to or lower than CPA (Tap).

CPA (Tap) is the stricter figure, because every install in it followed a tap on that ad. Use it to judge a keyword's bid, and read the gap between the two as the installs the ad brought in without a tap.

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