The next leader in the race of best b2b marketing blogs to follow is Moz. Be careful, the concentration of useful information on SEO rolls over here.
Moz describes how to promote websites using link building techniques, how to write structured posts and prepare your pages for efficient promotion, how to boost client retention with proven SEO reporting practices, etc.
Among blog authors, there is Moz co-founder Rand Fishkin, well-known online marketing practitioners, and marketing scientists from Moz (Cyrus Shepard, Dr. Peter J. Meyers, etc.). All these "marketing stars" regularly share their experience and professional examples, so you can be sure that the time spent studying materials on this blog will bring a return in the form of sales (and money, of course).