Falcon Heavy Launch Cost/price = 100Million
Probability of Successful Launch = p{0,1}
Cost of Satellite = Sc
Expected Value of Falcon Heavy Launch Service = 100,000,000*p
If the cost of some satellite is less than 100,000,000*p, the opportunity cost of the wasted payload space has negative expected value.
If you use the value of the successfully launched satellite to the launcher instead of the cost, the argument becomes even more financially compelling.
There is no way SpaceX threw away a ticket to LEO worth 50+ million dollars(assuming p>=.5) to someone on a tesla car.