Like others mentioned, Amazon sends the question via email to verified buyers as "some user have a question and needs your help" and there is a button to answer their question (which opens the browser).
I saw lots of "I don't know" answers to questions, I guess Amazon realised this also as now they put "I don't know" button to emails.
I saw lots of "I don't know" answers to questions, I guess Amazon realised this also as now they put "I don't know" button to emails.