Five years to the month after it was founded, cross-blog social networking widget MyBlogLog will be closed down by Yahoo! in January, we're hearing from sources close to the project. MyBlogLog is a service that shows blog writers and readers the faces and profile information of other MyBlogLog users that visit their sites.

MyBlogLog 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. It's also likely to anger bloggers all around the web.

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.

Here at ReadWriteWeb we scraped a feed from our MyBlogLog page of the new users just added to our community, then reached out to thank them for their support and welcome them personally. That was just the beginning of what could have been a very valuable source of data. 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.

Looking at the ecosystems beginning to form around Twitter, Facebook and other user data - MyBlogLog may just have been ahead of its time. The service isn't alone among potentially world-changing technologies acquired and then starved of support at Yahoo! We've asked Yahoo! for comment and will update this post if we receive any.

Image via CrunchBase

We called co-founder Eric Marcoulier for comment and he offered the following perspective: "So much of your company's long term sucess when it's acquired is based on the amount of executive juice it has. The only way it survives and flourishes is if you have an executive champion who promotes it internally. Shortly after we were acquired we were transfered away from our champion and under someone who didn't feel the same way about MyBlogLog. In those circumstances, things simply slow down.

"For any startup that has earn outs, and this didn't affect us, you've got to keep in mind that in 3 months you could be reorganized and the new guy could shut you down. The picture that gets painted early on when you have your product champions can change in a heartbeat and it's important for entreprenuers to consider that when looking at the deal terms."

R.I.P. MyBlogLog.

Update: Chris Yeh, head of the Yahoo! Developer Network, has responded over at the YDN blog: "Frankly, it's no secret within Yahoo! that we're actively discussing the future of MyBlogLog. However, it's also true that we have not made any final decisions at this point. Is a shutdown on the table? Sure, that's an option. But there are other options as well."