Picking an online music store ought to be no more complicated than choosing between grocery stores. But if you're going to buy more than a few songs a month, you may find yourself in the kind of long-term commitment associated with inking mortgage documents.
That's because the big online music stores (for example, Apple's iTunes Music Store, Microsoft's MSN Music, Napster, RealNetworks' RealPlayer Music Store and Rhapsody, Sony's Connect, Yahoo Music and Walmart.com Music Downloads) don't all sell the same bundles of bits.
Instead, they offer songs and records in different file formats. Almost all of these restrict you to certain programs and music players, and almost all arrive cocooned in a layer of copy-control software to stop you from sharing your purchase with the neighbors.
You can't quickly or conveniently convert these files to another format. Your downloads today may dictate the hardware and software you buy years from now -- and conversely, what you own now can determine where you download in the future.
This applies to anybody with a Mac or an iPod: The iTunes Music Store is the only major online shop to offer full support for Apple's hardware. But if you've bought one of Sony's digital-music players, the only store with compatible downloads is Connect. And if you own a player compatible with Microsoft's Windows Media Audio files, you'll do best at sites that sell music in the same format.
Those factors aside, here's what to look at when considering these stores.
Inventory: The selection at the weakest online store dwarfs that of the biggest land-based store. But we've all been spoiled by the likes of Amazon.com; we rightly expect an online store to carry every song ever committed to vinyl, tape or CD.
You can blame the music industry for some of these gaps. Some artists only let their work be offered for download at one store, while others don't allow their music to be sold as bits at all -- an act of denial that would make the Flat Earth Society proud.
But stores share responsibility too; not all have signed deals with enough record labels or put full effort into stocking back-catalogue material.
Apple and Napster both claim inventories of more than 1.5 million songs. Real's stores stock a bit more than 1.2 million; MSN Music, Napster and Yahoo cite catalogues of more than 1 million songs; and Wal-Mart carries about 600,000 songs.
But none of those numbers means anything if a store doesn't carry the one artist, album or song you want. Searching through the catalogues of Apple's store requires downloading and installing its own software; other stores let you window-shop.
Pricing: All of these stores sell songs for 99 cents each (except Wal-Mart, which charges 88 cents), with per-album rates typically ranging from $9.99 to $13.99 or more. In other words, a single should cost the same everywhere, but you can pay more for an album at one site than at another. But there's no clear pattern to this; temporary promotions excepted, nobody has a real edge.
Fast Forward