We notify you when your balance drops below $1, which should be enough time to top-up again. In the future we're thinking of having that notify N days before we estimate your balance going to 0.

By the way, the site uses trackingco.de for analytics, so I can give you some free balance to return the favor :)

This service is for pinning files on IPFS. Say, for example, that someone wants to publish a paper that they want to always be available (even if a government tries to take it down). IPFS helps by making distribution p2p, as anyone who accesses the file can also redistribute it until it expires from their cache.

Pinning removes this expiration, and serves the file forever. Eternum provides that service, making sure the file will always be on at least one node, and thus always accessible.

It's not really comparable to Dropbox or S3 at all.

Our marketing currently assumes you're familiar with IPFS, as I don't think the service will be too useful directly if you aren't. Maybe we should change that, though.

Another avenue for this is, for example, what IPFessay (http://ipfessay.stavros.io) does: it publishes a file on IPFS and then invites you to click a link to Eternum to pin it, even without knowing how IPFS or Eternum work.

From my understanding it's more like web hosting with IPFS than file storage with Dropbox. You could put up an HTML web page and instead of running your own IPFS node in order to let people access your site, they run it for you.

Well, your argument could be pointed against Amazon S3, because they charge while Google, Dropbox and Microsoft offer storage for free.

This is IPFS, the use case is different.