Google hopes everyone using AdSense likes the new look of their ad units, as there won’t be an option to go back to the old ones.

"Although it’s not possible to opt out of the new designs, we hope that you and your site visitors will find our new ad formats clearer and more attractive," Leslie Chiang said on the Inside AdSense blog.

The lines between ads have been removed, and the ‘Ads by Google’ phrase now appears in the lower right corner of the ad block. After testing the refreshed ad units, Chiang said Google has found AdSense has greater visual appeal to viewers. "They also perform even better for publishers and advertisers."

Colors and fonts won’t be changed as the new ad units rollout through the AdSense Network. That should be a relief to webmasters who may have feared some rapid code work would be required of them. Matching colors and fonts to one’s site tends to help ad performance.

Naturally the move has rapidly attracted opinions, some going deeper than the superficial changes. ZDNet’s Donna Bogatin wondered when the company’s founders lost their philosophical way:

What happened to the Sergey Brin and Larry Page infamous advertising is evil in search theory developed while idealistic Stanford students?

A little evil is good for the (Google) bottom line.

Here is the new look; click it for a full-size view, and drop a note in the comments about it on your way out: