Curious if anyone can provide best insights - how exactly does one split-test FB ads? I'm aware that you just make a similar ad and run it. But specifically, how do you insist it rotate 50% of the time head to head against another one? Do you run it at the same time as in Adwords? or do you run one at a time? And if you ran 3 at a time, are they split 33-33-33% percent of show time? It seems like FB optimizes the ad with the best CTR, but I'm not certain. Thanks for any insights