The key thing I noted when I visited the home page of DropBox is that I instantly understood what they do.

I compared DropBox to the Box website. After wandering around several pages, I left without being 100% sure if they could do what I wanted.

The ability to offer a clear, concise message should not be undervalued.

Its what stood out to me too.

That said, even as a techie who has worked on and with dropbox products, ive come this far without ever really relying on it. And I dont see that need increasing over time.

I love dropbox, but im a bear on it long term.

If only they'd give users the option for 1-click encryption before uploading/syncing. It could work especially well with Dropbox since it has only native apps anyway. We already know they are "next" on NSA's list for companies to target (at least in an official manner, they've probably targeted them for a long time unofficially).

I belive that might not have been initially viable since part of their service is the mirroring of files that are already uploaded. If you and I both have the same mp3 in our dropboxes, only one of us have to upload it initially, then the second person to add it would only have it 'synced' in their dropbox since the file checksum matches. If we both locally encrypted it with our own keys then the resulting file on the server would be different. It'd require more storage space and more bandwidth — more operating $. Maybe not though :-)

I think the key reason is it would be significantly slower for the end user rather than the incremental increase in storage cost. Bandwidth remains the same since Amazon doesn't charge for incoming and de-duping doesn't affect outgoing.