It's kind to be cruel, so long as it's self-directed.

At least, that's the marketing lesson of the summer as companies flood the channels with self-effacing spots. Why would a company knock itself? Well, apparently it's one way to shatter a negative perception.

In its latest ads, McDonald's (NYSE:MCD) sings the praises of its premium salads. After gushing over fresh ingredients and quality dressings, some of the spots close with a "Yeah, McDonald's" kicker -- as if it's a shock that Mickey D's has something worth paying up for.

Read: "We've been marking down fatty, fried junk food to a buck just to move it, but now we've got something really good for you."

Earlier this summer, Wal-Mart (NYSE:WMT) ran an ad about a family that couldn't afford a summer vacation and wound up buying tropical gear at Wal-Mart to create their own Caribbean backyard getaway. The message? We're Wal-Mart and we're cheap.

For the latest in promotional self-flagellation thank Taco Bell. The Yum! Brands (NYSE:YUM) chain just launched a contest where diners who order large soft drinks can win free gasoline debit cards. Cool refried beans, you say?

Taco Bell has been giving folks free gas for years? Of course. That's the point. It's the brash below-the-belt kind of marketing that endears the viewer to the company by spinning its shortcomings.

In a flagging economy, consumers root for the underdog. The flamboyant days of Pizza Hut rockets and E-Trade (NYSE:ET) monkeys gone: Modesty delivers a more unifying message. Humility pays, but we bet no one will be so bold as to say how well.

Have you noticed the trend in self-effacing marketing? Do you think it's a passing fancy or will the marketing modesty become a permanent fixture? All this and more -- in the The Motley Fool Take Discussion Board. Only on Fool.com.