Some lessons bear repeating —and relearning— over and over again. Here’s a good example: Companies that treat their own employees well have better reputations with the public at large.

Advertising Age (a sister publication of Workforce Management) today had results of the 2007 Harris Interactive Reputation Quotient study that lists the U.S. companies with the best (and worst) reputations. Here are the top five companies, ranked by the percentage of people who believe that the company comes across as genuine and authentic in its actions:

1. Johnson & Johnson
2. United Parcel Service
3. Google
4. Kraft Foods
5. Walt Disney Co.

The surprising finding here was how well Google placed despite spending very little on advertising or marketing.

“Google is the perfect example showing reputation does not correlate with ad spending,” Robert Fronk, senior VP-senior consultant, reputation strategy, at Harris Interactive, told Ad Age. “The positive perception of how you treat your employees, your corporate social responsibility efforts, and your products and services and the amount of media that can generate probably trumps any ad spend they would ever want to make.”

Treating workers well would seem to be a no-brainer, an easy thing to do. Yet surprisingly, a lot of organizations just don’t get it or do it. That’s why strong and caring leaders like Herb Kelleher of Southwest Airlines are so rare and hard to find. But as the Google ranking in the Harris poll shows, treating workers well has a bottom-line impact, yet doesn’t take a lot of marketing or advertising to make happen.

The survey also points out this sobering note: that big business, in general, did not fare well in the study. Some 71 percent of consumers said the reputation of corporate America is either “not good” or “terrible.”

Google, and all the other companies that fared well in the Harris study, show that there is another way. Treating people well, whether it be customers or employees, is a best practice that can dramatically affect the bottom line. But it makes me wonder: If it clearly makes so much business sense, why do so many companies fail to do it?