It's tough to lose friends, but we've recently had to say goodbye to PostRank and Collective Intellect. They've been great partners to work with -- and we're really still friends! -- but both providers have had to shut off their APIs, which we've depended on for a good chunk of our metrics in the Power 150.

Collective Intellect is bearing down on its main business, providing semantic analysis of social media chatter for brands, and PostRank just got straight up bought by Google -- you'll have to speculate as to how their powerful tools and talents will be absorbed into the search giant in the future.

So what's all of this mean for the Power 150? Well, we decided that we'd roll up our sleeves and replicate some of the technology we lost. Our Product Manager Rahmin Pavlovic and Software Samurai Kevin Meltzer have tapped into APIs from Facebook and Twitter, and with them we've turned each of the social networks into standalone metrics. At this point in time, we don't have to explain why these sources of conversation (and traffic) are relevant barometers for the influence of your blog, and thus we've given them equal weight, 40 points apiece.

So how's it work? Every night, we're going to take a peek at your RSS feed and pull out the five most recent posts. Then, with the Facebook and Twitter APIs, we'll pull down the number of likes and tweets for each of those posts, as well as the total number of links to your blog's main URL as the cherry on top. Finally, like every other metric on the Power 150 -- Todd Score excepted -- we'll scale those raw totals on a curve amongst the raw totals of every other blog on the list.

Like every other metric on the list, you don't have to do anything differently, and there's nothing you have to opt into or sign up for. The only caveat to that is that , as a blog owner, it's a good idea to make sure that your blog has a functioning RSS feed, and that this feed is auto-discoverable. Your auto-discoverable feed is how we track your posts, and so it's essential that it works!

Have some questions about the changes? Let us hear them in the comments.