Is Lena in danger of becoming one-hit wonder?

With her poppy first song “Satellite,” the 19-year-old Hannover native charmed European viewers and won the event in Oslo by a landslide. The tune went on to reach the number one spot on music charts in seven countries, and her debut album “My Cassette Player” sold 400,000 copies.

But according to daily Die Welt, pre-sales of the new single, set for release on August 6, are “sluggish.” Ratings have reached 63rd place on Germany’s music download portal Musicload and 33rd place on iTunes, the paper said.

When she returned from the Grand Prix to her hometown in May, Lena was greeted by 40,000 ecstatic fans, but ticket sales for her tour, set to begin in April 2011, are also lagging. Her bookers reserved only the biggest arenas, such as Berlin’s O2-World, which has 17,000 seats and hosts major artists and events from around the world. Ticket seller Eventim shows that Lena’s tour doesn’t rank among the top 10 most popular events, though.

But her record label Universal Music isn’t concerned yet, the paper said. The newly minted pop star continues to jet around Europe giving interviews and promoting her album. Recently she logged her 4,322nd interview, and then got on a plane to Sweden, the paper said.