Beyonce's £50 million Pepsi deal opened up a wider debate on celebrities, advertising and promotion last year, with Mrs Carter seemingly having no qualms selling sugary carbonated drinks despite helping Michelle Obama's Let's Move fitness campaign.

For years, Pepsi and Coca-Cola have been criticized for targeting children, with many arguing that when consumed to excess the drinks have negative effects on long-term health. However, in a recent interview with Flaunt, Beyonce rejected the idea of hypocrisy, saying, "Pepsi is a brand I've grown up seeing my heroes collaborate with. The company respects musicians and artistry. I wouldn't encourage any person, especially a child, to live life without balance."

The singer - the biggest R&B star in the world - has been heavily criticized for lending her name to the brand.

"Knowles is renting her image to a product that may one day be ranked with cigarettes as a killer we were too slow to rein in," Mark Bittman wrote in the New York Times. "From saying, as she once did in referring to Let's Move, that she was 'excited to be part of this effort that addresses a public health crisis,' she's become part of an effort that promotes a public health crisis."

The Pepsi deal is a lucrative yet complex affair. It not only includes traditional advertising spots, but also gives the drinks company a stake in her art. Essentially, Pepsi is opening up new investment avenues while the singer doesn't have to worry about finding the cash to support her projects.

The deal was the biggest celebrity endorsement in recent years, though by no means the only one. Alicia Keys assumed the mantel at Blackberry, as did for Intel and Justin Timberlake for beer Bud Light. Taylor Swift signed a huge deal to be a "brand ambassador" for Diet Coke.

"I wanted to share some news with you, because we're finally making it official with one of the great loves of my life. Diet Coke," Swift said in a strange YouTube video announcing the Coke deal in January.

There has been some serious aggressive criticism towards the recent spate of celebrity endorsements. Dan Charnas, author of The Big Payback: The History of the Business of Hip-Hop, told Variety, "What the f*ck does Alicia Keys have to do with Blackberry? And when has Alicia ever had the aesthetic to be a creative director of anything except an album? It doesn't make any sense to me, other than it's a company trying to make something that's inorganic more organic. It's the co-optation of cool."

As Beyonce clearly has no real connection with Pepsi, or should she be more upfront about her reasons for promoting the brand - money. The rapper Ice Cube is upfront about his endorsement of Coors Light, "You just wanna make sure at the end of the day everybody's going to be happy," he said, "I want to be happy, I want Coors Light happy, and to do that I want us to sell a hell of a lot of beers and make their projected numbers."

BeyonceBeyonce Performing at the Glastonbury Festival

Beyonce's Pepsi Deal Is One Of The Biggest In History