Loved the post, here's a feature request for you: I organize an annual conference [1]. All of our attendees get a free tshirt. We purchase all of our tees from

Loved the post, here's a feature request for you: I organize an annual conference [1]. All of our attendees get a free tshirt. We purchase all of our tees from a single manufacturer (say American Apparel) and let the attendee tell us the size they want before we finalize the order. The problem is that attendees often don't know what size will fit them, and sometimes guess wrong and end up with a poor fit. Anything you could offer us to help here? [1] http://2016.cascadiajs.com http://2016.cascadiajs.com