EAC is a clever branding phrase for web campaigns that get conversion feedback based on in app signals matched to fbclid/gclid (and possibly other identifiers). I’ve seen various names for this workaround that gives more levers of control vs mostly automated app promo, which can indeed result in better efficiency as few people here commented.
So, click persister > join key (user_id/purchase/transaction_id/etc) > API based conversion signal emitter = BOOM
If the advertiser has at least one savvy engineer in-house who knows how to read Platforms’ API documentation or dev guides they can make the custom solution/workflow for their own app. However, engineering time costs in addition to opportunity cost of not have them working on the app (and possibly cost of some 3P tools you might wanna use to capture & store identifiers). In that regard, depending on pricing & client’s data sharing (in)sensitivity this can be a packaged solution that saves time.