We used to get more than 30% of our site visitors as abandoned users but now we are getting less than 10%. As per my suggestion, I have personally helped them in integrating Google AMP pages with their existing sites so that they can easily see how it works for an average user (not technically sound). The entire process was smooth and easy just like any other changeover you might be familiar with. They did not charge us anything extra because there were no such changes or additional efforts required from their end. This feature has really changed things up for me when people visit one of my websites - they stay longer instead of immediately leaving without taking action!