The “Big Five” — WPP plc, Omnicom Group, Publicis Groupe, Interpublic Group of Companies (IPG), and Dentsu Inc. — lead the ad industry through sheer size and global reach, each boasting intricate histories and extensive workforces. Based in London, WPP leads the pack in revenue, followed by New York-based Omnicom.
Recap Table: The 7 Best Advertising Platforms in 2025 PlatformAudience Size LinkedIn Ads 700 million pros YouTube Ads 2.7 billion users Microsoft Ads Smaller but engaged X Ads 335 million users3 more rows •
Is $100 enough for Facebook ads? $100 can be a good start for small, targeted campaigns or testing purposes on Facebook.