Or even better, a mobile app install ad on mobile and a FB app ad on desktop. I'd love to see one of these experiments that isn't trying to get website signups

Or even better, a mobile app install ad on mobile and a FB app ad on desktop. I'd love to see one of these experiments that isn't trying to get website signups / sales which is something FB is notoriously bad for. I spent a few years at an SPMD, and I would really advise against anyone who doesn't know exactly what they're doing to use the FB self-serve anyway...