Last month, I swapped my personal blogging over to Tumblr. I may still post the occasional “essay” over here, but the short multimedia posting action on Tumblr seems the right fit for now. Check it out here.

As many of you know, I’ve been focused on a new digital music venture for about 2 years now, starting with a pretty “web 1.0″ path (write business plan, create financial model, talk to VCs) and subsequently wising up to a more pragmatic approach (tap friends and 401k, build and iterate on product, attract people to site).

I’ve been working with a talented group of friends over the last year to get this new service, called 8tracks, off the ground.  We launched an alpha version of the site at the beginning of the year.  Informed by feedback, our team — including our first full-time developer, Rich Caetano — launched a beta version of 8tracks about a month ago.  We’ll be bringing in new users over the next 2 weeks, before public release a week from Friday, on August 8th.

The new 8tracks blog is up and running, and our first substantive entry explains more about 8tracks.

Please check it out and let us know what you think!

While I’m on this list-making tip, I just noticed SAI is now tracking the most valuable digital startups. This is a useful list and includes details on how the valuations were estimated. I like the fact that the list is global and features some surprises, at least for me:

• FB and Wikipedia top the list at $9bn and $7bn, respectively
• London-based Betfair is worth as much as Craigslist ($5bn)
• Habbo and Linden Labs both worth > $1bn
• Ning already worth >$500m (that seemed quick)
• Zazzle at $250m (also seemed quick)
• Surprisingly, Meebo is worth nearly as much as Yelp (both ~$220m)
• USV investments make the list: Etsy ($115m) tops Twitter ($75m)
• Wesabe doesn’t make the cut though rival Mint does ($50m)

Fascinating stuff.

I wrote on Wed about the notion of “total attention” as a useful metric by which to evaluate music or other websites — but didn’t explain my thinking or actually run the numbers.

As so many have written over the last decade, a large and growing proportion of GDP comprises products and services that are (or can be) rendered in bits. As it becomes ever cheaper to create, copy and distribute bits, scarce resources in production (broadly defined) are increasingly giving way to scarce resources in consumption – i.e. consumer attention. As an aside, this is why I’ve long believed (and Chris Anderson eloquently wrote a few years back) that the most significant driver of value for digital products is really just “matchmaking” or filtering or discovery. That is, helping people find those bits of greatest interest from the digital haystack, so to speak.

In any event, if consumer attention is the most precious resource in the digital value chain, then its proper measurement is critical. Further, I’d argue that the more attention a web offering can command, the greater the opportunity for monetization, all else equal. If a person visits more pages on a website, listens to more minutes of a webcast, or uses another web-based service more frequently, there are more opportunities to place promotional or branding messages, whether priced on a CPM, CPC, CPA or other basis.

Likewise, a user’s choice to spend more of his “disposable” hours in the day on a website/cast/service also suggests that he ascribes greater value to it, and — again, all else equal — there is a greater likelihood he may be willing to pay directly for some aspect of that product, whether priced on an a la carte (commerce) or ongoing (subscription) basis.

To measure the total attention that a web offering commands, 3 factors must be considered:

• unique visitors
• frequency of visits (e.g. avg visits/unique)
• average “stay” per visit

While average stay per visit (e.g. minutes on site) would seem a logical measure to assess the magnitude of a visitor’s activity on site — since it tracks the total minutes of attention granted — another, perhaps more practical measure is page views per visit. Page views per visit is useful b/c it (1) generally corresponds to new ad placement opportunities (with each page refresh), and (2) ensures that a user is “active” on the site and does not simply have the browser open in the background while, say, writing an email.

So then total attention can be defined in 2 ways:

• unique visitors x visits/unique x minutes/visit = total minutes of attention
• unique visitors x visits/unique x pages/visit = total pages of attention

I used compete.com to rank the top 10 music sites on the latter basis (the former really won’t make sense until online audio ads move beyond a nascent stage). As this post has gotten a bit overlong, I’ll include these rankings in a new post.

If one assumes advertising (or other sorts of attention-based business models) will be the primary driver of revenues for online music services — or really any online services — then a total measure of attention is useful in establishing the value of the service.

I’ve generally presented music sites ranked by “people” (compete.com’s version of unique visitors). But really a total measure of attention should reflect:

• unique visitors
• frequency of visits (e.g. avg visits/mo)
• average “stay” per visit

I checked a few of the top music sites on the average stay measure and found some intriguing results:

I’m guessing that some of the reason Live365 ranks so highly has more to do with its user base (older, more passive) than specific site features. But it is somewhat surprising.

A bit off-topic but I’m annoyed.

I’m a big fan of Apple. In years past, I’ve subscribed to .Mac though of late haven’t really seen much benefit. I noticed the annual charge came through on my bank account last week. No notice was given in advance, but I called Apple’s customer support team and they quite nicely reversed the charges, noting it’d take 24-48 hours for the refund to be issued.

A few days later I’d not seen the reversal on my account so I sent another email to Apple, and they said the refund had been processed, as noted, but timing would depend on my bank. So I called my bank (Citibank) this afternoon, and they indicated it would take 7-10 days for the credit to hit my account.

I don’t understand this. When I buy something at the corner shop, it might take an extra day or 2 before the charges show up. So why should it take one of the largest global banks at least a week to process a credit. Who’s sitting on that cash for that week? I’m a bit skeptical.