People all over the geek-o-sphere are mourning the loss of social bookmarking service Delicious, which Yahoo! announced internally today will soon be shut down. Delicious wasn't the only acquired startup service the company admitted it was going to drown in a well like an unwanted kitten, though.

Yahoo's excellent location sharing clearinghouse Fire Eagle, the social events calendar and the innovative browser music player FoxyTunes will all be merged into other products, but at least they'll live. Due to die: MyBlogLog. Let's take a moment to appreciate what MyBlogLog could have been; it captured and made available so much data about the social web that it could have been the most important of all those services.

Above: the leaked slide from an internal Yahoo! deck that was posted online today, ironically by MyBlogLog co-founder Eric Marcoulier.

In December 2009, ReadWriteWeb reported that the service was on the chopping block in the short term, but it struggled to survive another year. Here's what we wrote about it at the time:

MyBlogLog is a service that shows blog writers and readers the faces and profile information of other MyBlogLog users that visit their sites.

It was a wildly innovative service that grew fast after launching and was acquired in January 2007 by Yahoo! for $10 million. It made a deal with users: Give us your personal information and we'll show you the faces of people who read your blog. That was a compelling offer and the resulting data amassed could have proven invaluable, had Yahoo! chosen to cultivate it and a developer ecosystem around it. That potential was so great, in fact, that sunset for MyBlogLog is downright tragic.

In addition to showing the faces of recent blog visitors, MyBlogLog also offered programatic access to activity streams from social networks that users associated with their MyBlogLog accounts. For example, Yahoo's Kent Brewster, now at Netflix, built a bookmarklet that would display the recent bookmarks on Delicious, photos on Flickr and job titles from LinkedIn of the latest MyBlogLog users to visit any given blog....

Yahoo! has let the service atrophy for years and will now put it to rest. To think that this service offered publishers and developers access to personal, demographic, taste and activity data of a website's readers - and yet that offering has in the end gone no where - that's downright crazy...

Imagine getting a feed of the LinkedIn job titles of all your recent readers and presenting that to a blog's advertisers. Both analytically and financially, there was so much potential in MyBlogLog. See our 2008 post The Significance of the MyBlogLog API if you're a social web geek and want to have your heart broken.

What's the crew behind MyBlogLog doing now? Building a very similar service called OneTrueFan, which just made a big announcement today. Good luck, guys, and watch out who you sell the company to, would you?