If anyone is interested in a technical intro to the setting there is a set of slides from John Langford at Yahoo Research (many good and standard reference papers cited in it): http://hunch.net/~exploration_learning/

A/B testing could be thought of as a sort of epsilon-Greedy strategy (particularly if such testing is carried out at regular intervals initially). While not enjoying the optimality characteristics of other algorithms, such an approach can in fact outperform in many practical cases :)