Currently within the Apple Search Ads platform there is only data on keyword performance before the install. Since my app has in-app purchases, I would like to be able to attribute app installs from Apple Search Ads to see which keywords have the best performance when it comes to in-app purchases.
I know attribution platforms like Adjust and AppFlyer are able to attribute app installs from Apple Search Ads, but we use Google Analytics and haven't been able to figure out how to.
You can implement the Apple Search Ads Attribution API. Full docs are located at https://searchads.apple.com/help/pdf/attribution-api.pdf or you can read my blog post on how I implemented the Search Ads Attribution API.
Once you get the Attribution data from Apple you can pass it to Google Analytics using the Campaign Measurement parameters such as utm_campaign, utm_source, utm_medium, utm_term and utm_content. See the Campaign Measurement docs.
I have also developed a platform to help track the performance of Apple Search Ads by keyword and In-App Purchases at http://kitemetrics.com/.
