If that’s your business plan, then sure. It doesn’t have to be. Lazy client devs will go the easy route and turn their users into products like you’ve described. Smart client devs who care about doing things better than the old way will understand that their users are customers and will have products and services that can be monetized by selling them to those users. Really smart client devs will recognize that their power users are actually their partners in business, and will form collaborative arrangements to mutually benefit from each other and build their systems accordingly.  

 The smartest client devs will realize that they’re coders and not business managers and will build a team around themselves to figure these details out. Flying by the seat of your pants won’t work at scale.