Let the Price Wars Begin: Amazon Follows iTunes

As of Tuesday, both Amazon and iTunes started offering music at 69 cents, 99 cents and $1.29. However, prices can vary from site to site. For example, while iTunes priced Lady Gaga's popular song "Poker Face" at $1.29, Amazon's selling it for 99 cents.

All downloadable music on those sites previously was priced at 99 cents, but the recording industry has been pressuring services to move to the tiered strategy. Once iTunes capitulated, the floodgates were opened. Hit songs in general will cost more, while music from an emerging artist might be priced at the lower end of the scale to encourage purchases.

Apple has also done away with copy-protection technology known as digital-rights management (DRM), which means customers can play songs on devices other than Apple's own iPods —such as Microsoft's Zune. The songs can be copied to any number of CDs, computers and music players, as long as those devices support the AAC encoding format Apple uses.