The Power 150 is a ranking of the top English-language marketing blogs in the world, as developed by marketing executive and blogger, Todd Andrlik. It's really as simple as that, except that the name isn't strictly accurate: It currently ranks hundreds of blogs written about pretty much every imaginable marketing discipline.

It's now housed on Ad Age, partly because we thought it'd draw some traffic and links for us, but also because both Todd and Ad Age figured it was a useful service to rank and showcase all these sources of information in one place, where thousands of readers could discover them. With more than 700,000 registered users on our site and a host of daily and weekly products, we also hope we can grow the traffic to Todd's creation and some of the blogs it highlights.

What Todd came up with is a largely objective ranking, which is probably why it's already gained such popularity among marketing and media bloggers. It uses a basic multimetric algorithm to obtain a final ranking based on the sum of five sources, four of which come from Alexa, Yahoo, Twitter, Facebook, LinkedIn and StumbleUpon. The last is Todd's own personal subjective measure. In the case of a tie, individual scores for a blog are weighted in the following order (from highest to lowest):

• Todd Points (1 to 15): As the only subjective measure in the Power 150 algorithm, 1 to 15 opinion points were assigned to each blog. Todd Andrlik values frequent, relevant, creative and high-quality content as well as unique visual appearance and style. The use of audio, video and graphics is also heavily weighted in the Todd Points.
  
  
• Twitter (1 to 25): The ubiquitous social network needs no explanation, and how we compute your Twitter score is pretty simple. We just grab the number of tweets linking to your 10 most recent posts, then we add in the number of tweets linking to your blog's main url, and we put it all together. Lastly, we take this raw total and scale it amongst all the other blogs on the list. What you get is a rough idea of how you compare to your peers in attracting Twitter links. While links from your own Twitter account are included in the totals, we don't consider how influential your individual Twitter account itself is.
  
  
• Facebook (1 to 25): Facebook scores are computed the same way Twitter scores are: We take your 10 most recent blog posts plus your blog's main url, find how many Facebook likes include links to these URLs, and then scale this total number out of 40 points. The influence of your individual Facebook profile is not factored into this score.
  
  
• StumbleUpon (1 to 15): This metric is based upon the total number of times a particular blog has been viewed by users on StumbleUpon. Note that this metric is not limited just to recent posts.
  
  
• LinkedIn (1 to 15): This metric, like Facebook and Twitter, is built from the number of times users have shared your 10 most recent posts, with the number of shares for your blog URL added on top. The number of connections to your profile and other similar metrics pertaining to your LinkedIn profile are not included in this number.
  
  
• Yahoo InLinks (1 to 30): Much like Technorati's InLinks count, Yahoo uses its Site Explorer to tabulate the number of links to a particular blog. We then scale this number down to a 30-point scale.
  
  
• Alexa Points (1 to 25): Alexa ranks sites with an algorithm that incorporates page views and reach (the percentage of all web users who have visited that particular site). For the Power 150, we take that rank and assign it a proportional score between 1 and 25 and factor it into a blog's total score.

As we said, credit for the idea and a lot of the hard work goes to Todd who is still responsible for assigning those Todd Points. But Todd also gives a shout out to the Marcom Top 100, a Dutch-language blog ranking that inspired him. Ad Age and Todd would also like to give a great deal of credit to the TechBrew crew, which automated his original system, as well as our web products team, who have made it the tool it is today.

If you have a blog listed on the Power 150, you can let everyone know where you stand with our easy-to-use javascript badge. Just find your blog in the list, click its badge icon and copy and paste the code wherever you'd like. As the rankings fluctuate day-to-day, the number in the badge will be dynamically updated, so your readers can see where you're ranked each time they visit your site. If you're the modest type, you can also grab a generic badge that simply lets people know you're on the Power 150 without divulging your ranking.