Apple Ads metrics are useful when they answer a decision. They are noisy when you stare at them without changing bids, keywords, screenshots, pricing, or metadata.
CPT is the cost of attention
Cost per tap tells you how expensive it is to get a user from the search result to your product page. High CPT can be fine if conversion and revenue support it.
CPA is the cost of an install or acquisition
Cost per acquisition is closer to business reality than CPT, but it still needs context: trial starts, subscriptions, refunds, and retention matter.
TTR is relevance feedback
Tap-through rate helps show whether the search query, ad, icon, title, subtitle, and first screenshots feel relevant enough to tap.
Conversion rate points at the product page
If taps are good but installs are weak, inspect screenshots, reviews, price, app size, localization, and whether the keyword intent is wrong.
CPT tells you tap cost
Cost per tap shows what you pay for store visits from Apple Ads. High CPT is not automatically bad if conversion and revenue support it, but it raises the bar for the listing.
CPA tells you acquisition cost
Cost per acquisition depends on what you count as acquisition: install, trial, subscriber, or paying customer. Use the event that matches your business, not the easiest number.
Conversion rate explains the leak
If taps are expensive and conversion is low, screenshots, reviews, pricing, or keyword intent may be the issue. Ads metrics should feed ASO decisions, not sit in a separate report.