CHICAGO (AdAge.com) -- It's time to unthink KFC -- again. This week, the chain is rolling out its first global tagline, "so good," which marks its fifth change in ad direction in almost as many years.

But this time, KFC plans to stick to its strategy. "We've been very impatient," said Javier Benito, KFC's exec VP-marketing and food innovation. "When you look at brands that have been with the same taglines for many years, they do well because they're consistent." He cited Nike and Coca-Cola as standouts.

KFC is struggling at home, but growing in Asia. The company believes one global message will leverage its scale, and the tagline itself works with a wide variety of products.

Waffling from fried to grilled and back has fostered confusion for KFC consumers. For example, most don't know the chain sells sandwiches, which is where much of the growth is. Compare that to rival Chick-fil-A, which has grown market share in part because of close association with its flagship fried-chicken sandwich.

But that's just one of the problems facing the brand. Mr. Benito said KFC needed a perception of balance on the menu and a value platform, which was introduced earlier this year and now comprises at least 8% of sales. Enter "Unthink."

"It has been a great advertising campaign for us to break from the past, but we felt it was a little narrow in that [it was] very closely linked to the product news," Mr. Benito said.

KFC's same-store sales fell 4% in the U.S. during 2009. According to Technomic, market share also declined 1.7 points to 30%, although the brand comfortably retains its market-leader status. According to Kantar Media, KFC spent $235 million during 2009, down from $255 million in 2008.

Technomic President Ron Paul said that KFC can rebound, but to do so, "they've got to find the right focus." "Obviously, going to grilled didn't seem to work very well, so they're going to have to try some other new products."

Mr. Benito said the tagline is the result of the combined efforts of Ogilvy, Sydney; Bartle Bogle Hegarty, London; and DraftFCB, Chicago. The tagline emerged in focus groups, when lapsed customers tasted the product and said, "It's so good." But in addition to tapping nostalgia, it also provides an umbrella that works for promoting grilled chicken, crispy fried strips or a value meal.

The chain is, moreover, shifting its focus from a "demographic to a psychographic," Mr. Benito said. Eating a bucket of chicken has always been a group activity, he said, so now KFC is reaching out to "socially connected people who are trans-generational." That means a teen on Facebook or her mother who reads blogs.