Do you ever feel like you're being watched—or experimented on—when shopping online? A/B testing is a standard practice companies use not only for marketing purposes, but in user interface design and user experience as well. Adjustments are then made over time to suit the preferences of users making use of the data gleaned from the testing. Can/should/do architects do this? What kinds of modifications have you done in environments you have agency over to better suit your experience of space?