Microsoft's assault against Apple on the pricing front continues, with the latest salvo coming from its Zune division. A recent advert contrasts the price of filling up an iPod with the subscription cost for its Zune Pass service.

Microsoft claims that it costs $30,000 to fill a 120GB iPod, estimating each song to be approximately 4MB and cost $1. By that maths, it would take 166 years and 8 months of Zune Pass subscription to rack up a bill of $30,000.

The Zune Pass, which isn't available in the UK (nor are the Zune players), allows users to pay a $15 subscription each month for unlimited, but DRMed, downloads. As of last November, you're allowed to keep ten tracks a month from Zune Pass for good.

It's proved popular with Zune owners, but hasn't enabled Microsoft to do much damage to the iPod overall - probably because (as Pocket-lint has previously reported) 48% of the average iPod's content has been downloaded illegally.