Apart from books, the 2nd product line Amazon introduced back in the 1990s was music CDs. Their catalogue of music is huge and, as you'd expect from this company, their pricing is highly competitive and they have great mail-order terms.
If you are stuck for a present for someone but you know their music preferences, what could be better then obtaining either the most recent release or a hard to find CD from the back catalogue of one of their favourite artists or bands.
If you are looking for CDs then this company is certainly worth checking out.