What can you learn from A/B testing for Product Management?

I have often used A/B testing for optimizations that are targeted towards sign-ups, lead generation and user engagement.

A/B testing
- Allows you to validate versions of a product element and test which works better for users.
- It enables you to test these changes without any dev release.
- Helps you to study user behavior that helps in product optimization.
- Provides the flexibility of testing from simple color change to revamped user flow.
- Allows you to test your new product launch version against the existing one. This definitely helps you to switch back when things don't go your way.