I've spent a lot of my career doing A/B testing, including doing that role exclusively for a number of years. I specialize in ecommerce, so maybe I have too nar

I've spent a lot of my career doing A/B testing, including doing that role exclusively for a number of years. I specialize in ecommerce, so maybe I have too narrow of a view here, but in that vast majority of cases, I am optimizing for revenue per visitor, which is a function of conversion rate and average order value. There are sometimes leading indicators like engagement, but in ecommerce, you're afforded the luxury of basing things on revenue or even bottom line. I really don't like the positioning of ALL A/B testing as unethical behavior where you're hostilely trying to take advantage of a user. It's quite the opposite. There are a lot of extremely poor user experiences out there and a quality testing program can help improve user experiences, remove risk from making sweeping changes, and help you learn more about your audience and market. The vast majority of the successful testing I've done is done around trying to HELP users navigate the site and product catalog, understand the product, and purchase the product. Attention spans are fleeting with online shopping and even the smallest points of confusion or friction can turn shoppers off. Additionally, often times I'll read into test results after a month or so to see if there were any issues with orders that might indicate purchases from disinterested people or misaligned expectations.