The business is/was connecting resale opportunities to brands and artists[1] so you'll have a fairly significant sales and marketing effort although typically you will pay sales people for performance so their compensation will track revenue.
But to give you some things to think about, if you have an engineering team of 15 engineers, median salary $120K, and an 'overhead' (office, health plans, insurance, etc of 60%) then that is $200K/engineer/year (or $3M/year or $48M for 16 years [2001 - 2017]) that is just integrating cost per engineer over time using constant engineering. You can put any function in you want for head count (does it grow exponentially? does it grow in chunks? etc) and then add a C-suite team (higher median salary) and an 'overhead' team (IT, marketing, HR, etc) and you can burn through that fairly quickly.
It is a useful thing to build models for this stuff as your 'pre-operationally-cash-flow-positive' costs are really the health and future of your company.
