As you know there are a variety of business models for companies. For some businesses the business model may be driven by the intended exit strategy. If the exit strategy is to go public then profitability is very important. If the exit strategy is to be purchased by a competitor because of the profile of their customer base, then profitability may be sacrificed in order to maximize customer aquistion. If the exit strategy is to be purchased by a expanding company to their user base, then a revenue model may be sacrificed in order to maximize user acquisition.
If the exit strategy is to be purchased for the quality of their technology the business objective may be simply to demonstrating the market value of the technology.
Of course the exit strrategy could be a combiniation of these.
In my [limited] understanding he customer is the person who pays the bills. the bills are paid at Dolphin through investment. Without revenue the bills are paid by investors -- Thus the investors are the customer.
I would propose that the "investor-customers" of Dolphin Browser are currently focused on an exit strategy which does not necessitate revenue or profit at this stage of business development. And that is their business model.