* No one seems to use American express, so let's remove it from payment options. Turns out, the site had a bug that made sure 100% of AMEX transactions would fail. By fixing, we picked up 6% in sales, and lost a UX associate who was (and probably still is) arguing to drop AMEX because analytics.
* Since very few people actually click the apply button on the job board, let's remove the apply feature. The idea was we could send candidate profiles to employers based on views instead of apply clicks. Had to revert this one.
* Same company: let's take job posts out of our mobile job search app because most interactions end on a job post (and a click on the apply button). Best ticket the next day, "I can't find any jobs in this job search app?"
* No one uses the UI customizer (dashboard colors, fonts, and preferences). 100% of the tickets the next day were from people who were PISSED BEYOND BELIEF that we removed their favorite feater. Turns out the customizer basically was invisible to our app analytics. Had to revert this and re-do two sprints of work because the other new features wouldn't work with the customizer.
In 100% of the cases, talking to actual users would have been beyond wise before using analytics data to make decisions.