A/B testing is the worst. I'm always on the bleeding edge of products I use and extremely tolerant about changes and regressions–to the point the browser I am using crashes every couple of hours, likely due to a longstanding threading issue–but I just cannot stand constant A/B changes. If you change the font of your website even once, I will know. If you tweak the spacing of some elements, I will know. If you change a color slightly, I will know. Even if you pretend like nothing changed at all, I can tell and it drives me out of my mind because something seems "off" and I must find what it is. I spent half an hour once searching for why Hacker News's text area font seemed to have randomly changed from Courier to Menlo before emailing 'dang in desperation to figure out what was different (turns out it was a new lang="en" attribute). Please, don't change things randomly and silently.