Why do campaign URL analytics also include source types like App Store Search or App Store Browse?

Hello everyone!

Why do campaign URL analytics also include source types like App Store Search or App Store Browse?

We have an App Store campaign URL on our website. First I wondered why the app units of our domain (under the Web Referrers tab) is lower than the campaign app units. After checking the details of the campaign, I noticed that the campaign also includes App Store Search and App Store Browse in App Units by Source.
That doesn’t make any sense to me as the campaign URL directly opens the product page. Or does that mean users went back to the Store, searched for the app later again and bought it then?!

Maybe I’m missing something. Can someone explain the resoning behind this?