The mighty cloud draws businesses and developers who seek its agility and productivity. But which type of cloud is best? We moved eBay Marketplace, a major eCommerce site, from a traditional infrastructure to a cloud model. We will present the strategic, technical and cost factors we weighed when deciding between cloud versus automation, and porting applications versus rewriting them. We will explain why we ended up with a hybrid: developing our own internal cloud while leveraging the massive infrastructure of public cloud providers.