The Washington Post

The megamerger of Omnicom and Publicis counts a significant percentage of major advertisers as clients.

The more they know.

Create sophisticated index. Take it to Washington. Hang out with the President.

Finally, companies have figured it's worth their while to try to reach you on your phone.

"Consumer switching" means each reader isn't as valuable to advertisers, and tracking them might not help.

Two of the world's biggest advertising companies are merging. Here's why antitrust regulators shouldn't let it happen.