Taco Bell's "Think Outside the Bun" was a memorable brand campaign that aimed to distinguish Taco Bell from its competitors in the fast-food industry by emphasizing its innovative and unconventional approach to Mexican-inspired cuisine. This campaign ran from 2003 to 2012 and was highly successful in rebranding Taco Bell as a fun and creative fast-food option.

Here's an explanation of the key elements and message of the campaign:

1. Slogan: The campaign's central slogan, "Think Outside the Bun," was a play on words that encouraged consumers to rethink their expectations of what fast-food Mexican cuisine could be. Traditionally, tacos and burritos were made with buns or tortillas, but Taco Bell wanted to emphasize that they were offering unique and imaginative menu items that went beyond the ordinary.

2. Emphasis on Innovation: Taco Bell used the campaign to highlight its innovative menu items that included items like the Crunchwrap Supreme, Doritos Locos Tacos, and the Fourthmeal (late-night dining). These offerings were unconventional and stood out from the competition.

3. Broad Appeal: The campaign aimed to appeal to a broad audience by showcasing a diverse range of menu items, from classic tacos to bold and inventive creations. This approach allowed Taco Bell to cater to various tastes and preferences.

4. Creativity and Playfulness: "Think Outside the Bun" conveyed a sense of playfulness and encouraged customers to be adventurous with their food choices. It invited consumers to explore new flavors and combinations.

5. TV Commercials: Taco Bell supported the campaign with a series of TV commercials that featured humorous and quirky scenarios. These commercials often portrayed people breaking free from conventional thinking and enjoying Taco Bell's innovative menu items.

6. Brand Identity: The campaign helped redefine Taco Bell's brand identity, positioning it as a fast-food restaurant that offered more than just traditional Mexican fare. It became known for its bold and imaginative approach to food.

7. Longevity: "Think Outside the Bun" had a successful run for nearly a decade, which is relatively uncommon for marketing campaigns in the fast-food industry. Its longevity suggests that it effectively resonated with consumers and contributed to Taco Bell's success during that period.

While "Think Outside the Bun" is no longer the active campaign , it played a significant role in shaping Taco Bell's image and menu offerings during the 2000s and early 2010s. Please note that my information did not be up-to-date, and there did have been new developments or campaigns related to Taco Bell since then.