I remembered long time ago when MP3 player is non-existent (at least to me), the term Walkman is exclusively to Sony. When we talked about walkman, we are talking to Sony. Sony launches the first Walkman (TPS-L2) on 1st July, 1979.
Today, 1st of July 2009, is actually the 30th Anniversary of Sony Walkman. Time flies but Sony still managed to maintain the Walkman label. Although the current model plays digital format content, the legend remains. Below is the latest walkman from Sony. A vast difference from the original one (see above).
From Straits Times,
Sony sold 30,000 Walkmans in the first two months after its launch, and 50 million within a decade.
That is a record.
If you want to know the history, click the link below.