web development is very easy.  I would consider the securities laws and balancing customer service and risk management to be the most difficult part.  However, a broker may have a completely different view on this than a programmer.  The marketing looks like it can be done through the same agencies that traditional faucets use to market themselves-where the CPM rates are dirt cheap-as well as traditional social media.
   Personally I have no experience running a faucet, but you are right that the real world is far more complex than the theoretical world.  The real world is where all poo hits the fan, and realize all the real world obstacles and limits.