system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do companies with perfectly good mobile sites want us to download their app so badly?

I don't get what they have to gain from me using their app over their website.
gpt
It's a marketing tool.

Having their app on your phone basically means they have their company now in your pocket. They know how much you check your phone. Now that their app is there they have an ad right on your phone! Push notifications? Perfect! 

Yes their website is amazing and very mobile friendly, but their website isn't on your phone, you have to go to it through another app. Downloading their own app basically means you just subscribed to their company and you are now their Guinea pig.