The cards, containing a code number that provides access to downloads from , have been on sale in Dixons since October, and now could be available from up to 16,000 Post Office branches.
A green 拢20 card provides a two-month subscription to Napster, with unlimited access to listen to Napster's library of more than 1m songs during the period. A blue 拢30 card lets users download and keep 33 songs. The idea is to give access to people who do not have credit cards or debit cards.
Leanne Sharman, vice-president of Napster UK, said: "It shows how far digital music has come into the mainstream."
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