Does Lark use my data to show ads?

No.

We will continue to focus on providing the best user experience in Lark. Ads are not currently a part of our product, and if we ever do decide to add them to the app, it will not be done without considering the full user experience. We take our customers' opinions very seriously, and will do everything in our power to preserve the product you know and love.

As stated in our privacy policy (and as a standard practice), Lark may use de-identified data in order to advertise to new customers, and improve the overall product experience.  Attracting more users benefits everyone using Lark because it allows us to make Lark better over time.

You can read Lark's Privacy Policy here:

http://lark.com/lark-privacy-policy/