I have been using Evernote since it first existed. Over those years I have been using it as my primary information repository. At one time I configured it to be used as part of a Getting Things Done methodology, which accounts for the current notebook structure.
For a long period of time Evernote was the only note taking app I used for both professional and personal notes. Certain professional notes that I did not want to risk sharing were stored in a notebook stored on my work computer and not synchronized with Evernote's servers.
Today I keep my work related notes in OneNote (See How I Use OneNote) and Evernote is my personal information repository. Web clippings are stored in Evernote, I use IFTTT applets to archive certain information in Evernote, and I forward certain emails that I want to be sure to retain to Evernote.
I pay yearly for Evernote's premium plan in support of the application.
Changes within Evernote's leadership has caused some to speculate whether the service could go dark. I've personally resisted migrating completely to another service, however I recently experimented moving my data out of Evernote to OneNote and DEVONThink. Neither services align 100% to Evernote, but I found DEVONThink to be best aligned of the apps I tried.