1. A computer program product, comprising: (a) a program configured to perform a method a broadcast messaging method, the method comprising: receiving a message for a plurality of subscribers and a desired number of suitable responses from a sender; broadcasting the message to subsets of the plurality of subscribers in a first round of waves; if the sender does not receive the desired number of suitable responses, rebroadcasting the message to subsets of substantially the same plurality of subscribers in a second round of waves; wherein broadcasting the message to subsets of the plurality of subscribers in a round of waves comprises periodically sending the message to two or more subscribers until substantially all of the plurality of subscribers receives the message; and (b) a tangible, non-transitory, computer readable media encoded with the program.