I like services on my local machine. While it is true I can't access all my passwords when I'm not on my main device, two things come to my mind right away:
1. I rarely if ever use any other machines. When I do, I easily memorize my passwords for common things I like to check. Usually these days I check them on my smartphone.
2. There are ways to get 1Password to work with Dropbox which in turns allow me to replicate what you guys are doing without having to exclusively use an online service.
Having said that, I believe you can still garner userbase, but my original question stands, what added benefit do you guys offer?
PS Site design is a bit hideous, a change may help.