Nothing to complain about here, really. If you are based in the US, you will soon be able to listen to 90-second previews instead of the 30-second clips that can be sampled right now on iTunes.
This is the letter that Apple itself has sent to record labels:
“We are pleased to let you know that we are preparing to increase the length of music previews from 30 seconds to 90 seconds on the iTunes Store in the United States. We believe that giving potential customers more time to listen to your music will lead to more purchases.”