[gregbarbosa]

I think the reasoning they are shooting for 24 is because their application seems to be based around contextual conversation. Having a retention period of zero pretty much eliminates context.

Apps like Snapchat, deleting the message as soon as it's viewed, wouldn't work when you want to apply a ton of context in the conversation. Too often I'm having a "conversation" on Snapchat but it's more like small snippets of text and a lot of me questioning what the other person said a few hours ago.

[schrodinger]

They're referring to retention on the server, not the phone I believe. The phone could store the message indefinitely even if the server didn't. The server just needs to hold it long enough for your device (devices?) to download it.