It's a question of markets, I think, and it's something we haven't really decided on. 1 hour covers IM, mostly. 8-24 probably covers most e-mail use (maybe?) What we don't want this to become is something like Rapidshare, and limiting file lifetimes is our attempt at not letting that happen. The service is designed primarily to share files with people you know personally, within a finite time period. But we'll see how it gets used, and maybe change our policy.