I had no idea this was coming.  I saw the Pepsi/iTunes ad early last week, but the Napster ad, "Do the Math" was a complete surprise. To sum it up, it basically says:

Do the Math. How much will it cost to fill up your player?

• iTunes + iPod (10,000 songs to fill) = $10,000
• Napster to Go + (choice of devices, 1M tracks available to fill) = $15/mo

It's back to the whole purchase vs. rental issue which is a personal decision.  I bet this is going to turn some heads though. Napster has almost exactly the same library as iTunes and works with more devices.  This will be interesting to watch over time. I wonder if Apple is working on an iTunes subscription model?

Oh and I just noticed the first 1000 people to sign up for a year of Napster to Go get a free iRiver H10 5GB Music + Photo player with FM radio built-in.

Napster to go also works with Portable Media Centers by Creative and Samsung ;).