Lady Gaga has come under fire for allegedly encouraging her fans to purchase multiple copies of her new single in a bid to boost its chart performance. The Poker Face hitmaker is preparing for a return to the charts following the release of her new song, Applause, on Monday (12Aug13), and she has launched a competition for fans in conjunction with the track's debut. Gaga has offered her loyal followers the chance to win tickets for her upcoming show at London's iTunes festival by sending her a screen shot of their receipt from purchasing Applause on iTunes. She writes in a series of posts on Twitter.com, "Screen shot your Applause purchase... (We will) choose 2 devoted fans to go with me to ITunes fest (sic)!... The 2 fans w (with) the most purchase/gift screen shots, radio requests, Applause selfies/video, will fly international to meet me + watch the show!... I'll choose the winners by middle of next week! Operation Applause Gaga takes you to iTunes Festival where you see 1 full hr (hour), all new music." She later added, "U.K. monsters (fans) thank you so much! I'm so happy to be climbing your charts again." The contest has sparked criticism that Gaga is urging her fans to buy multiple copies of the single to drive it up the charts, and editors at Examiner.com claim many devotees are spending more than $300 (£200) each on copies of the track in a bid to win the competition. Many online critics claim the contest is giving Gaga an unfair advantage over her chart rivals.