[Timothee]

What are the ongoing running costs though? Serving the scanned images? Sure, but if the only way to add more data to that bucket is to keep buying notebooks, that should be fairly safe. The hosting costs should be very low compared to the price of the notebook. And if you continue accessing your files, you're likely to want to buy more notebooks.

[dasil003]

Are they hosting the images? I assumed it was relying on Dropbox/Evernote/OneNote, or at most a limited time drop.

[xerophtye]

They have their own app which integrates with dropbox/evernote/onenote for user conveneince