Earlier quoted context omitted.
They can do it using O-3 visa, its the same classification as an O-1 but of a different type. Assuming they incorporated the startup, and then immediately received funding and started visa process (in that order) they can use percentage points (from zero to +++ whatever investment they received) as part of their case. USCIS is more interested in profit/revenue than any other metric.
O-3 visas are issued to the spouse and children of O-1 visa holders. Did you mean something else? http://www.uscis.gov/working-united-states/temporary-workers...
http://www.uscis.gov/working-united-states/temporary-workers...