IPFS is just piece of the puzzle. Filecoin, Bitcoin like technology (but about files instead) is meant to combat this issue. Similar to how you pay Dropbox or AWS to host your files, you'll have IPFS hosts that you'll pay to rehost your content. Or, you'll have your own public daemon that you can "pin" your own content. In the end, people are not willing to give out disk space for free, therefore Filecoin will exist.
http://filecoin.io/ < built by the same guys behind IPFS and meant to be used together
> In the end, people are not willing to give out disk space for free, therefore Filecoin will exist.
Disk space is one parameter of the equation though. Bandwidth and uptime should be considered too in order to estimate the effective amount of resources a node adds to the network.
Given enough peers over time, neither bandwidth or uptime should be an issue. If an incentive based system like Filecoin were to take off, and there's a market to exchange that currency, then it may actually be a viable business just to set up farms that host content. Kind of like a hosting service, but with indirect customers.
What if you pay the network to host your blocks by hosting some other blocks from the cloud, at some m:n ratio? The cloud (some random peer) could periodically check your block inventory and make sure you were still holding up your end.
Really, this whole concept is similar to torrents. Either ratio-based (upload at least X % of what you download), or HnR based (don't download something and refuse to seed it.)
http://filecoin.io/ < built by the same guys behind IPFS and meant to be used together