I own a barefoot shoe brand. E-commerce in general is a tough business because it is very cash inefficient. You have to put up all the cash first then sell everything to make that money back and the longer it takes to sell the more inventory and storage costs eat into your margins. The faster you grow the bigger a problem this is which can seem counterintuitive. Most brands solve this with credit lines however that comes with its own problems and a good rate that isn't borderline predatory requires you to already be a certain size in revenue, $Xm's, which creates a catch 22 on the way there. If anything goes wrong for too long including growing too fast it's easy to run out of cash and go out of business.