You can tell a lot about a band's status by the amount of bootleg merchandise they attract - and the pavement outside the Astoria is plastered with Placebo T-shirts and posters. Non-devotees may be surprised. To many, the trio made most sense at the height of Britpop, when the appearance of a mouthy androgyne (frontman Brian Molko) banging on about sex and drugs made a refreshing break from the geezerish, checked-shirt consensus. Their last album's underperformance (in Britain, at least) suggested their best days were behind them.

Such heretical views would, however, get you lynched in the Astoria. The set is underpinned by the buzz of low-level hysteria. A good foot or so shorter than fishing rod-proportioned bassist Stefan Olsdal, Molko is an unlikely sex symbol. His size, along with his tight jacket and slicked-down, jet-black hair, make him look like a ventriloquist's dummy who has jumped off Olsdal's knee and is making a bid for freedom.

But when Molko steps to the front of the stage for a guitar solo, the shrieks of approval wouldn't be out of place at a Justin Timberlake concert. When he removes the jacket to reveal a Byronic white shirt, you think of old Beatlemania pictures and half expect to see a flustered bobby, helmet askew, holding back the crowd.

Sometimes Placebo merit such adoration. Techno-enhanced songs such as Taste in Men and Pure Morning are terrific, as huge, black and ominous as storm clouds, while Slave to the Wage is a hypnotic, krautrock-inspired rush. But almost all the slower numbers are atmospheres in search of a tune and most of the material from new album Sleeping with Ghosts retreads old ground.

That is the problem with settling into cultdom: you end up preaching to the converted. Placebo appeal to the eternal adolescent who wears black, reads Rimbaud and flirted with bisexuality at a party once. This is their strength but it also makes them lazy. Molko calls Liberty X "fucking shit" and the crowd scream their approval; it is a cheap shot at a sitting target. One new song, he announces, is inspired by James Dean's predilection for having cigarettes extinguished on his chest, a revelation that surprises no one.

At such moments you wish Placebo would grow up, but with fans this fervent perhaps that's the last thing they should do.