I'd go low on fake credibility, and high on real customers wearing your shirts. The vast majority of sales is shirts, with some related apparel and accessories. Scaling a campaign that has momentum is quite different from getting something started from scratch. But I go back and forth between "testing" strategies and "scaling" strategies. So I think this will work for new products/niches, too. The appeal of the offer has to be very strong. That'a a big point.