Yesterday I read an interesting article on the Chorus America website titled "What Happens After the Premiere" by Don Lee. The article brings up some interesting points, one of which is that many works are commissioned for a premiere performance and then fall off the map (at least for a certain amount of time). He points out that there is a distinct marketing advantage for a group to present the premiere versus the 2nd or 3rd performance of a piece. But, to be honest, I'm not sure the audience really thinks about this as much as the ensemble does.
The audience is there to hear great music, and they are there to be enriched regardless of whether that performance is the very first, or the 2nd, or the 100th. As a composer, I am of course a huge proponent of commissioning and I think there are myriad benefits, but I am also a huge proponent of supporting pieces after they have been premiered. Given all the work that goes into bringing a new piece to life, I think we need to be careful to not just premiere a work to pomp and circumstance and then forget about it.
In his article, Lee points to some good programs and partnerships that are striving to address this issue. Composers certainly have some responsibility here and must do everything they can to ensure that the works have life beyond the premiere performance.