- Macfadden Communications Group
- Madavor Media Llc
- Maher Publ
- Maker Media Inc.
- Making Music Magazine
- Mango Life Media
- Mansueto Ventures LLC
- Maplegate Media Publishing
- Maritime Publishing
- Martha Stewart Living
- Marvel Entertainment Group Inc
- Maven
- MC Aby Publishing
- McLean Communications
- Media DC
- Media Out Loud, LLC
- Media360LLC
- Mental Floss Llc
- Meredith Corporation
- Metrocorp, Inc
- Midwest Outdoors
- Miller Sports Group
- Milwaukee Magazine Inc/Mcgeary
- MissouriLife
- MIT
- Modern Farmer Media
- Moffly Publications, Inc.
- Morris Media Network
- Morris Publishing Group
- Morris Visitor Publications
- Mother Jones
- Motor Trend Group
- Motorsports Marketing
- MovieMaker Magazine
- Murphos Publishing
- Music Maker Publications, Inc.