• marciahoo - Marcia Welter, a previous moderator for WebmasterWorld, blogs about the search marketing industry, SEO and interesting forum threads.
• Manhattan Marketing Maven - Danny Flamberg blogs about all aspects of marketing including marketing online.
• Market Position - A group blog about search marketing from WebTrends, owners of Web Position Gold.
• Marketing Experiments Blog - Real-time data, insights, answers, and advice from Flint McGlaughlin’s team at MEC
• Marketing.fm - Lee Jones Eric Friedman post about online marketing and advertising. Labs.
• Marketing Logic - Matt Bailey, one of my favorite conference speakers, blogs about search marketing, analytics and usability.
• Marketing Pilgrim - Andy Beal’s super stupendous blog on search engine industry news.
• Marketing Profs Daily Fix - With managing editor, Ann Handley, this group blog posts on all things marketing with participants ranging from Eric Ward to Stephan Spencer to BL Ochman.
• MarketingVOX - Previously Marketing Wonk, this post I-Search publication founded by Tig Tillinghast.
• MasterLink Search Marketing Blog - Mark Barrera and Kimber Cook write about search engine optimization.
• Matt Cutts - Google’s famous engineer and search spam fighter dispels wisdom, insight and squashes SEO myths.
• Media Buyer Planner - Online media publication from the same folks that bring you MarketingVox.
• Media Relations Blog - Blog about new media PR and media relations.
• Metaverse Business Blog - A blog about Second Life marketing.
• Micro Persuasion - Steve Rubel from Edelman PR on new and social media, web 2.0 and marketing online.
• Mike Grehan Says - Old school SEO Mike Grehan blogs about his world travels and the SEO column he writes for ClickZ.
• Mike the Internet Guy - Recent winner of best local search blog, Mike Belasco writes about all aspects of marketing online.
• Mikkel deMib Svendsen - I have no idea what this blog is “really” about because it’s in Danish and my 9 months in Denmark 14 years ago isn’t helping any. What I DO know is Mikkel from many, many search marketing conferences in his signature bright, and I mean bright colored suits talking about some serious online marketing, not just black-gray-white hat search engine optimization. If you do speak Danish, I’m sure you’re in for a treat. Tak!
• MIMA Search Marketing - A blog for the in-house and agency search marketers in Minneapolis and St. Paul.
• mimaseosemgeeks at Yahoo! Groups - Discussion thread for search marketers in the Midwest.
• Modern B2B Marketing - Jon Miller of marketo blogs about BtoB marketing online.
• MoreVisibility SEM Blog - The team at MoreVisibility cover industry news & events, online advertising, CPC, analytics and updates on the Search Engines.
• Morrison - Observations about the search marketing industry from Liam Morrison in Ireland.
• Mr SEO - Joe Balestrino’s SEO blog.
• MSN Sandbox - Where MSN posts beta applications for testing.
• MSN Search’s WebLog - Official blog for MSN Search.
• Multilingual Search - Andy Atkins Kruger and friends around the world blog about search engines and search marketing news happening outside North America.

N

• Natural Search Blog - Group blog covering natural search engine optimization.
• Net Business Blog - Matt Coddington writes about affiliate marketing, CPA, PPC, SEO/SEM, eBooks, domaining and web development.
• NewspaperGrl - Janet Meiners writes about internet and affiliate marketing.
• New PR - Digg style community for new media public relations stories - started by Constantin Basturea of Converseon.
• Niall Kennedy - Self proclaimed RSS geek with previous work experience at Microsoft and Technorati, posts about blogs, feeds and business.
• Nielsen Technical Services Blog - Another long-time Minneapolis based SEO blogs about the search engine marketing industry.
• NLC Internet Marketing Blog - A light posting group blog from the folks at non linear creations.
• No NonSense Internet Marketing - A true geek in the best sense, Bruce Hopkins markets his own sites and blogs about SEO and AdSense.