Instead of sending a pass-phrase encrypted ZIP file via email or IM beyond auto-delete feature, you go to this website, input the information and share the URL with the person of choice.

My grandfather wouldn't know what to do with an encrypted ZIP file. A lot of my friends wouldn't either.

Yes, difference in ease of use is certainly there and not ignorable. But wouldn't the need to send URL and pass-phrase via two different channels would be rather difficult to communicate to 'grandfathers'? Not an impossible task but, as someone who built consumer security products in the past, it's not ignorable either.