Be aware of a firm called shoppingspreetoday.co.uk, they offer?? a £250 curry/dixons voucher on the premise that you fulfil various offers through their affliated companies.
The companies vary, all internet based but some well known including Napster.
I had to subscribe to 8 offers and when subscribed and fulfilled as per instruction you should receive a credit on your shoppingspreetoday account. Now this happens quickly on some, slowly on others and not at all on most.
Of course I complained to shoppingspreetoday (which their website suggest I do), who emailed me back to say that they have no control over companies providing me with my offer and told me to go jump (to put it politely)
Anyway with Napster being one of the companies, I rang to cancel the subscription and told them the reason why (as they had not credited me). The girl there said they were not affliated with such organisations.
These all leads me to believe its a scam, dont know why but my advice, and you may see things on ebay alluding to this, dont bother, it is a complete waste of time. My only saving grace was signing upto betfair, which I got free credits for and ended up winning £150, which I quickly banked (you can ask me how I did it if you wish).