It used to have a payment form but I felt like it wasn't polished enough, so now it just says to email me for a (free) account.
I still use it every day for my own notes, so I suppose it was a success in that regard. I've also got a few friends on it too.
Does it need to be an Evernote replacement, or can this be a Chrome extension / etc that eventually stores in your Evernote account itself? I did read the text at the bottom of the website, but one thing to do note is that people trust the 'Evernote' brand for their data storage. You can offer this on top of Evernote/Onenote as a separate extension/layer.
That's a really interesting idea though. Maybe I could make it cloud backend agnostic..