A plethora of promises — or none at all

Utilitarians are supposed to have difficulty accounting for our obligation to keep promises. But utilitarians also face difficulties concerning our obligation to make promises. Consider any situation in which the options available to me are acts A, B, C… n, and A is utility maximizing. Call A+ the course of action consisting of A plus my promising to perform A. Since there appear to be a wide range of instances in which A+ has greater net utility then A, utilitarianism obligates us to make far more promises than even the most expansive views concerning our obligations to make promises would acknowledge