The secret of Adele's success? No festivals, tweeting – or selling out

She refuses to headline Glastonbury, bans her hits from advertising campaigns and won't turn her life into a soap opera. Adele has revealed the five-point plan which turned the singer into the world's most successful – yet reticent – pop star.

The Tottenham-born singer's latest album 21 has sold 5 million copies and currently sits atop the US Billboard chart for the ninth consecutive week. At 11 weeks, she holds the record for the longest consecutive stretch at number one by a female solo artist.

Yet relatively little is known about Adele, 23, who stopped sending personal tweets two years ago, just when her celebrity contemporaries began using Twitter as a confessional.

In an interview with Q magazine, Adele says that, despite huge commercial offers, she refuses to "sell out" and despises artists who exploit their fans for financial gain.

Rule number one in the singer's plan is no advertising tie-ins. "I think it's shameful when you sell out," she says. "It depends what kind of artist you wanna be but I don't want my name anywhere near another brand. I don't wanna be tainted or haunted." Adele attends every "strategy meeting" and approves every decision personally.

Rule number two is to restrict interviews and avoid Lady Gaga-style ubiquity. "I don't want to be in everyone's face. I'm a big music fan and I get really pissed off when it gets like that ... and I don't want people to get like that with me."

She won't tolerate the traditional marketing scam of record labels re-releasing albums with extra tracks to make fans buy a record twice. "I was furious when they did that on [her debut album] 19. I said 'No' and they did it anyway. Just mugging off your fans."

Rule number four: Adele won't play Glastonbury or another festival. "I will not do festivals. The thought of an audience that big frightens the life out of me. I don't think the music would work either. It's all too slow."

And finally arenas, such as the 18,000-capacity O2 Arena and their ilk, are also out. "We had three nights on hold at The O2 and I was like 'I wont play a festival. You think I'm gonna play a fackin' arena? Are you out of your mind?' I'd rather play 12 years at the Barfly [small venue for indie bands] than one night at The O2! So I've made all those decisions and some people are pretty mortified. They think I'm mad."

Paul Rees, the editor of Q, said: "What's become lost in the Lady Gaga-era is the confidence in the idea that less is more. A large element of Adele's success is that she remains something of an enigma and we don't know everything about her."