Another long-held media rule is falling by the wayside.

Magazines traditionally considered their cover “art” that was not to be sullied with paid advertising.

So much for that theory as Time recently ran a small ad for Verizon on its labels on the cover of its magazine. Sports Illustrated and others are going to follow suit.

Newspapers once followed the same rule about front-page advertising, but gave it up years ago. Now many not only run paid ads on the front page, but also slap coupons on it.

It’s just another example of how journalistic standards are slowly chipping away as the business side of publications are increasing in power.

“Native” ads that look like editorial copy but are really paid ads have become commonplace. They are designed to confuse readers who often think the copy is written by a real journalist when they are really the same as any other ad.

While Time’s initial cover ad is miniscule, you can bet that magazine ads will continue to grow in size and cost.