I think a fantastic platform would be health, including optometrists, dentists etc. Especially optometrists because if bigger chain stores start offering afterpay (e.g. Specsavers and OPSM) then the amount of growth would be substantial, for the benefit of all three parties. How many people turn away from optometrists because they feel like they can't afford glasses when they really need it?!? Or dentists for a simple clean or fillings?
