Though she was yet to release debut album The Family Jewels, she had tremendous belief that her popstar dream would become reality.
But the singer, who performs under the Marina And The Diamonds moniker, wasn’t simply planning to have a few hits and then quit - she had world domination in mind.
“I’d love to be as big as Kylie or Madonna,” she said. “It will take a while but I will get there.”
A year later her first album had entered the charts at No 5, and spawned the radio-friendly singles Hollywood and I Am Not A Robot.
An impressive start, but for someone with sights set on becoming a global icon in the Kylie-Madonna mould, disappointing.
Diamandis feels that she was “slapped down” by the press in this country for saying she was unhappy with the way her career was going back then.
“Well, if I’m honest, the British media had a different reaction to that sort of thing,” says the 26-year-old ahead of her gig at the Queen’s Hall tonight, rescheduled from last month due to vocal problems.
“As Brits, we’re supposed to be self-deprecating, and I was slapped down for daring to say I wish my album had sold better and that I was more well known.
“It’s weird though, because I was asked about the whole thing again and rephrased it slightly to say I felt like a failure for underperforming, and suddenly all these people were writing ‘I can’t believe she thinks she’s a failure, she’s done really well’.
“They were the people that said I’d underperformed and criticised me for wanting to be bigger.”
The singer, whose surname is Greek for Diamonds, shines even brighter on new album Electra Heart, which stormed into the UK charts at No1 and includes her biggest-selling single to date, Primadonna.
Diamandis used the break-up of her last relationship as inspiration and created a sexy blonde alter-ego to shield herself from further heartache.
“I read a quote that to avoid homewreckers, you have to become one,” she explains. “That was my starting point. When a relationship ends, you feel like you never want to go out with anyone ever again.
“It’s embarrassing to admit that, but self-preservation kicks in, and that led to thinking, ‘If you don’t want to have your heart broken again, you must then become a heartbreaker’, and Electra came from that.”
But she points out that Electra Heart isn’t an alter-ego, as such. “I figure she’s a metaphor for what it’s like when you’re heartbroken. Everything is taken to the Nth degree - everything about her is super-feminine and pink. The blonde hair conveys purity and innocence, while actually being something more sinister.
“I wanted to play with the idea of the female ideal and identity, and how, when you’re not compatible with someone, you start to become what you think they would like.
“Essentially I wanted to make a gimmick out of love,” she adds.
She goes on to say the tracks Bubblegum Bitch, Homewrecker and Primadonna are about someone who doesn’t need anyone anymore.
“Everyone wants to be like that, because being a victim is embarrassing.”
Diamandis says she’s excited to be coming back to the Capital next week for her rescheduled show and promises that the voice is “better now, if still a little fragile”.
“I love Edinburgh, I really do. I’m looking forward to going up to the Castle and doing some shopping -but obviously the gig, too.
“There’s a lot more production in the live show now,” she continues. “The stage is going to be converted into a motel room.
“There’s a TV and sofa, and a hat stand for costume changes... it’s exactly how I imagined it, so I’m super happy about that.”
Marina And The Diamonds, Queen’s Hall, Clerk Street, tonight, 7pm, £18.50, www.thequeenshall.net
Going to the gig? Tweet a review to @edinburghpaper using the hash tag #EENreview