Trying to understand developer policies

[Mardubec]

Hi, Im a developer and recently my app got rejected because of "The product or service is integrated with streams or content from another service. The application is integrated with other services (e.g. Youtube) in a way that is prohibited" . My application is about finding similar songs, the input is users favourite song and output is a list of similar songs based on the input. Afterwards, you can play the similar songs for 30s (preview) and choose, whether you wanna listen to it on spotify or youtube.

the problem my app got rejected is because it is also using youtube api together with spotify api, i can understand that. What i dont really understand, that sites like https://www.chosic.com/playlist-generator/  exists without any problem

I'm wondering, why they can do this but i can't? Im literally trying to do the same thing.

Thanks for your answers!

[Ximzend]

That's because in the past, you didn't need to request a quota extension.

[Mardubec]

well, but why those sites can still exists?