However, a big part of what makes money is what is happening behind the scenes. Countless are the pretty store fronts I've seen where the storage are is in complete shambles. Amazon have understood this, not even Amazon's mother would not be able to call it pretty but my oh my the fierce logistics monster hiding behind the not so pretty store front.
I'd like to call the goal 'Zero Incremental Transaction Cost Nirvana'. That is the state when your x+1 transaction does not cost you a single penny. Admittedly that is difficult in the physical world but should always be the aim. But take the Apple or Google Stores for instance, the x-1'th download of Angry Birds is getting pretty darn close to zero transaction cost.
But that means you need to take a good hard look at your internal processes; how is accounting systems talking to business intelligence, is accounts receivables connected to your bank, are all your supply chains automated, is your customer service department equipped with the greatest productivity tools there are? Basically it's the boring un-sexy stuff that will make you enormous amounts of money at the end of the day.
So if you're hiring an e-commerce 'expert' make sure they understand concepts like information supply chain automation, inventory turn over rate, API's, call centre management, accounting processes, procurement and all the other bits and pieces of a business. There are a lot of people that can pimp a store front, far fewer that can fix the actual store.
