LOS ANGELES: Britney Spears has allegedly disappointed concert promoters with the initial sales of her Las Vegas gigs. The 31-year-old singer  Spears recently announced a two-year residency at the Planet Hollywood Resort and Casino on Sin City’s famous Strip. But sales allegedly got off to a bad start, as Radar Online writes that the first 16 shows from December 27 to February 22 have only a few sold-out gigs. “After spending hundreds of thousands on promo, they expected to instantly sell out all of the first 16 shows, but they didn’t come close!” a source told the website. –BT