He built it because he was looking for the best blogs on marketing, PR, branding, etc., and could only find a consolidated list in Dutch. So he set about developing an English language version and that's what you'll find here.
His scoring is a blend of popularity (Google pagerank+subscribers from one Bloglines feed+Technorati rank) and his subjective score.
There are a ton of fantastic blogs to explore in this list! I still haven't got through checking them all out. After his top 150, he lists about as many "honorable mentions."
With so many excellent blogs on marketing, I'm very honored that Golden Practices--especially being niche specific--is on this list (presently at 182). I owe my readers, and Todd, a big thank you for that.
Be sure to check out some of the other 295 blogs he has identified. And if you want to search these blogs for specific advise, click on his Kitchen Sink link and do a keyword search. For anyone with marketing questions, this is a HUGE resource!
Thank you for creating this, Todd!