Before the innovation of mobile app, all business were online using website as their main premise where their address is based on the website URL. So when people share the website URL in different platforms, they send with a suffix of online analytics understandable part called UTM for their tracking. This UTM tracking allow analytics to find from which source this visitor got this address (also other identification like medium, campaign, content, term). this information are stored in cookies in browser when the same user comes next time (so their journey is recorded and matched using this)
So all this websites can be accessed from any public Browser and so the address is universally similar format and cookies will be used for tracking
BUT for the apps is not the case. iOS has its own store, androids has its own store and similar apps marketplace as well. And not all app analytics tool speak same language in terms of attribution. And there is no such things like cookies in mobile apps
Example : Google can understand UTM in the playstore link and store in google play report and then send this to Google analytics but iOS store doesn’t send this information to Google analytics.
And a main user requirement on Attribution is they want to send the collected information to advertising publisher where they need to know whether their campaign successful (which is similar like conversion pixel ads company place in website)
And if you are going to rely on UTM level information, you cannot send information. So in mobile app ecosystem, they need mobike app Attribution platform to
For more info on how this Attribution works, read here > https://www.appsflyer.com/blog/mobile-app-attribution-important/
The list of factors to consider before buying a Attribution platform