I don't track the organisation that people work for, and unless I need to contact them to send the login link, I don't keep their email address at all. The original frustrated text you type in is never stored either.
We do track and show on our front page what broad topics the signs were about that have been created, and what the common reasons were that the AI gave for rewriting them. We do this just so we've got a graph of what most signs are about and how they get improved.
If you opt in via our cookie notice, I use Google Analytics to see how people are using the site, where they're clicking, and to see if there's anything I can improve to make it more user-friendly. Google Analytics is blocked by default and only runs if you accept analytics cookies (you can change or withdraw your choice at any time using Cookie Settings in the footer). I don't share any information with any other parties or advertisers, other than Google (who provide the AI via Gemini and optional Google Analytics).