YouGov has released its BrandIndex Rankings for 2012, which compares BrandIndex Buzz scores of brands across major consumer categories in 10 countriest: the USA, the U.K., Denmark, Finland, France, Mexico, Norway, Saudi Arabia, Sweden and the UAE. Along with determining which brands generated the most buzz throughout the last year, the study also reveals the most improved brands of 2012. YouGov asked its respondents just one question, “If you’ve heard anything about the brand in the last two weeks, through advertising, news or word of mouth, was it positive or negative?”. The score of each of the brands was calculated by subtracting negative feedback from positive feedback. View some highlights from the research below.

Coca-Cola has tapped US pop country singer Taylor Swift as a new celebrity face for Diet Coke. The brand, which last year celebrated its 30th anniversary in the USA, will feature the 23-year old lady in its multi-platform campaign, which is expected to include more than just adverts. According to Ad Age, “executives close to the company noted she will not be involved in the company’s Super Bowl campaign.” Apparently, it’s because the young celebrity, who is gaining her power quite fast in the entertainment business, currently doesn’t have the superstar presence of such performers as Beyonce, who has been tapped by Pepsi and will be headlining the Super Bowl halftime show sponsored by the brand.

Coca-Cola US is piloting vending machines, which accept payments made via a mobile device —the new initiative was launched through the company’s partnership with the Isis joint venture created by AT&T Mobility, T-Mobile USA and Verizon Wireless.  The iconic beverages giant is not the first one which provides its consumers with such an opportunity (for instance, Starbucks offered it in 2011), but it is still a great move for the company.

IKEA Australia builds its new campaign on the “always say yes” philosophy. The retailer is encouraging Aussies to adopt a positive attitude for the year of 2013 (at least) and just let good things enter their lives. The new campaign, developed by The Monkeys, Sydney (the agency behind the hilarious “Have a Gö” promotion), is already launching on TV and in digital (including the heavy presence on the brand’s official Facebook page throughout the year).

Red Bull is giving wings to young people in virtually all the spheres of modern life, from extreme sports to arts. The energy drink is rolling out its initiative dubbed Red Bull Curates: The Canvas Cooler Project in the USA, inviting emerging artists from various backgrounds (and working in different media) to display their art pieces and meet art dealers at the SCOPE Miami fair during Art Basel, an international contemporary art show, in December.

The Diet Coke brand, which this year celebrates its 30th anniversary in the UK, is launching a new campaign, designed to evoke powerful overwhelming emotions in every woman. For the maximum effect of the new promotion, the brand has brought back its iconic Diet Coke hunk, who will appear in a new advert of the brand, which will be unveiled on the Diet Coke’s Facebook page at 11:30am on Monday (28 January).

Taylor Swift is helping the Keds sneakers brand to roll out a U.S. campaign, dedicated to “brave girls,” who are not afraid of living their lives to the full. The 23-year old American singer-songwriter is known for her playful nature (in particular, she likes to write songs about guys she broke up with), so Keds thought she could be a true role model for the brand’s target audience, young females.