[callmeed]

Regarding those services that offer "unlimited storage", I think they are really banking on the fact that many people _won't_ use enough space to cause the company a loss. Sure, there are heavy users, but when it all averages out, the company (hopefully) makes money.

Also, you have to read the terms of some services closely. IIRC, some of the online backup services are limited to "personal use only". They have separate pricing tiers for business backup (because they know those customers will use more).

[rs]

That's called "over-selling" - its a pretty common model amongst any resource intensive businesses, which reminded me of a blog entry on the Dreamhost blog where Josh Jones makes a connection between the recent finance market debacle and over-selling: http://blog.dreamhost.com/2008/10/22/how-to-make-money/

Edit: the blog post is meant for light reading