I was offered the exclusive program first and I declined, I felt like it wasn't worth it to throw away years of building an audience on webtoons for a platform I don't know much about and I can't guarantee an audience on. The non-exclusive program sounds good though since there isn't really any risk with it.
Is your comic on the platform yet?
I think maybe because it's way different from their regular comics that's the reason they contacted you about it? they're probably trying to expand their library into more genre's.
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On another note, I've asked them some questions regarding the ownership and the ownership is completely the creators for the non-exclusive program and you'll be able to take your comic off the platform if you want. (I haven't asked about the exclusive program though)