There are a lot of unanswered questions regarding SanDisk's slotMusic, mainly due to the limited details – like no info on content or pricing - as the product was unveiled today. While the reaction from analysts and the press is mixed, most skew towards being skeptical.

By and large, the slotMusic effort seems like another gambit to help retailers benefit from the digital music environment, and to reestablish the album as the primary product over the digital single. And why not? It certainly can't hurt, and may even generate some incremental revenue. But a mass-market product this is not.

As a removable memory product, microSD cards are handy ways to expand the capacity of portable devices like mobile phones and the MP3 players that support them. They also make for easy transfer of content from one PC to another (similar to a USB thumbdrive).

But as a content distribution platform, they've historically fallen short of the mark. There was been a push to use the format to deliver movies to mobile phones in the UK and the US, to no avail, and there's no reason to believe it will work much better with music.

Let's be clear: This is really about bringing music to hundreds of millions of mobile phones in the market today with microSD card slots. It's hard to imagine anyone would prefer buying a slotMusic card at the store, loading the music to a computer, to then transfer to an iPod, when simply buying from iTunes or (or stealing from P2P networks) is far faster, easier and cheaper.

Uber-fans may pick up slotMusic cards once they start offering additional content than what is already available - like music bundles including video, album art, lyrics, interactive liner notes, etc.; none of which will be available at launch - but the rank-and-file will be harder to convert.

The mobile music environment, meanwhile, is still struggling. Buying tracks remains cumbersome, the pricing is all over the map, and awareness among music fans remains nascent. If the mobile and music industries properly bundle these slotMusic cards with new devices at mobile outlets, there's a good chance they could introduce new fans to the mobile music experience. But, who wants to walk around with a pocketful of postage-stamp-sized memory cards for their mobile phone?

Then, there's the cost. Labels are basically buying the microSD cards from SanDisk, filling them with content, and then wholesaling them to the retailer-just like what they do with CDs. While neither labels nor SanDisk will discuss what the wholesale cost per card is, they concede it will be more than what CDs cost.

So you have a format that costs more than CDs to acquire, for a product that will sell for about the same cost of a CD, meaning labels will make less per slotMusic album than for a CD. The cost to the consumer will likely change (read: increase) once labels start loading these things up with more content, which would improve the value proposition. But, clearly, this is no CD replacement.

A more comprehensive analysis of the slotMusic effort must wait until more details come to light.

See below for a roundup of reaction from around the web:

Reuters: "The conundrum for SanDisk is that the very audience it would most love to endorse this format-young people who use their mobile phones and portable computers as social and educational lifelines-are already comfortable buying songs online."

BusinessWeek: "The question to me is the need for physical distribution at a time when, if you're not happy with digital downloads, then the CD is working just fine."

New York Times: "Unlike so many of the Frankenstein concoctions to come out of the music industry, SlotMusic, from what we know so far, does not impose any annoying compromises on users. For some, it may even be a good value."

LA Times: "Like many new formats before it, slotMusic faces major challenges in winning over mainstream consumers. Music industry executives say that they aren't sure it will catch on but that they want to experiment with new ways of distributing their work."

Ars Technica: "In a world where we can easily purchase all the music we could ever want online without ever having to set foot inside of a Wal-Mart-and increasingly, purchase it wirelessly right from our mobile devices-exactly which segment of the market SanDisk is going after remains a mystery."

Coolfer: "An unknown is to what extent consumers desire a tiny physical product that works with mobile devices -- mostly phones."

Silicon Ally Insider: "To us this sounds like a reasonable way to extract a few more dollars out of brick-and-mortar shoppers, who are still responsible for the majority of the industry's revenues."