Shazam is a “must have” in every Android phone. But I was surprised to see that in my Nexus One the application was not opening Amazon MP3 Store app but Amazon web site where I could not buy anything. After a little bit of research I found that I was not the only one experiencing this issue and that it's Amazon the one blocking other applications from using Amazon MP3 Store app (version 1.6), according to this report.
However, it looks like the Nexus One shipped with a newer version of the Amazon MP3 Store app (version 1.6) and this method of linking now results in an exception.
Shazam without a direct link to buy the song is almost useless. I hope that this issue is fixed soon.