Notebook is one product in Zoho's much larger, 35+ business and productivity application portfolio. Zoho has been a profitable, bootstrapped, privately-held company for over 20 years; we've been offering free (and ad-free) productivity apps for more than a decade. While some of our products are free, others are paid. Paid products subsidize our free apps. Free apps bring more awareness to our paid apps and brand in general. Our business model is as simple as that. There's no hidden agenda here to sell user data for ads.
Interestingly enough, privacy policies usually have a lot to do with business models. Since Notebook is powered by the success of our other applications, we're not looking for funding or advertisement revenue. This means we simply have no need to read your notes or sell your data. We are the biggest users of our products. In fact, our entire business runs on Zoho. We treat your data the way we treat ours.
All of your notes are securely stored on Zoho's infrastructure, with multiple data centers in the US, Europe, and Asia. Your data is encrypted in transit and at rest. For our European friends, if you create your Zoho account in Zoho.EU, your data doesn't leave Europe.
If you have questions on any of these points, please contact us: firstname.lastname@example.org