As the trains from the Underground in London arrive in the station, you hear the public service announcement “Mind the Gap.” This simple reminder to watch your step between the train and the platform is a perfect metaphor for Q4 in ecommerce.

Revenue spikes. Expenses spike too. The gap between what comes in and what goes out can widen dangerously if you’re not watching it. Mind the gap between your revenue and your operating expenses. Mind the gap between your inventory spend and your disbursements. Mind the gap between what your dashboard shows and what your bank account actually holds. That gap is where cash disappears.