Question: I've tried searching for the answer but couldn't find it. Do the notes stored in Google Keep use space from the Google storage? Or is it free and unlimited like a Google doc in Google Drive?

EDIT: that's too good to believe they would give unlimited storage for pictures and audio recordings.

Any update?

Answer: 
It seems there is no limit for Google Keep storage according to [this article](http://www.techradar.com/news/internet/web/google-keep-vs-evernote-vs-apple-notes-1139656).
As per the Google Product [forum answer](https://productforums.google.com/forum/#!topic/docs/_mgdBX6y53A;context-place=topicsearchin/docs/category$3Akeep$20storage$20space) no data attached to Google Drive account.