They could, but SpiralFrog doesn't appear to be interested. In essence, SpiralFrog offers extended sampling -- convoluted trial runs of music. Perhaps later it plans to offer tracks without Digital Rights Management technology, maybe even cheaply, but right now its offerings are laden with usage restrictions, available only in the unfriendly Windows Media Audio format, and apparently designed to self-destruct unless you visit SpiralFrog at least every month to renew your tracks (I'm no expert, but can you not work around this by winding your computer's clock back a few months? It's worked for other software).

Worse, the downloads are not compatible with Apple's iPods or iPhones, nor -- bewilderingly -- with Microsoft (NASDAQ: MSFT)'s Zune, despite the downloads' WMA format. It appears that you can't even listen to SpiralFrog downloads without being connected to the internet, as Windows Media Player has to validate the files due to their copy-protections.

Fine, but with all those limitations, surely SpiralFrog has an upside? I'm not a staunch defender of iTunes, using it pretty much only when some secret Santa gives me an iTunes gift card (I'm a die-hard eMusic man, for what it's worth), but relative to the paces SpiralFrog puts you through, the ease of iTunes' use and the breadth of its catalog is nearly worth the price of admission.

SpiralFrog presently boasts around 700,000 songs, versus iTunes' 6 million, not to mention all the latter's video and ringtone offerings. As for peer-sharing piracy networks like LimeWire, the pickings are always a craps shoot, dependent upon another user sharing what you're seeking, but I'd venture that a lot of SpiralFrog's catalog -- much of it courtesy of partner Vivendi Universal (LSE: VIV), which recently bailed on iTunes which in July passed on renewing its standard contract with Apple and can pull its catalog from iTunes at will -- is floating around, free to use as you please.

SpiralFrog isn't terribly difficult to navigate, but it's definitely a study in patience and persistence. Forget about downloading albums with one click -- you have to download each song track by ad-sponsored track, and it takes two or three clicks, each with substantial load times, before you can download a song.

All this clicking is ostensibly in the advertisers' interest, but I'm unconvinced that the ads are really that evident. I suppose I was expecting some intrusive interstitials or dancing Flash banners, but the ads -- mostly music- or Army-related -- rest quietly on the periphery, as with most websites. Based on SpiralFrog's FAQ page, I anticipated having to remain on the site when I tried out a download, perhaps being shown a video ad while it was loading, but not even. I was able to begin my download, then go hack away at this Shakespeare uninterrupted while waiting for my brand new song to arrive. If I'm a music label swapping my assets for a mere banner ad, I'd be unimpressed.

Limited catalog, cumbersome downloads, tight limits on use: Who's the audience for this? Cubicle dwellers who just want something to drown out their colleagues, maybe, or 13-year-olds who find SpiralFrog less daunting than digging up some nudie pics (doubtful, actually). Not too impressive a demographic for advertisers. Unless Apple sees a parade of defections like Universal's from labels balking at its rigid pricing, I'd wager SpiralFrog will croak long before iTunes.

[Thanks Fog City Dave for corrections]