Duff has since expanded her repertoire into pop music with the release of three RIAA-certified platinum albums: Metamorphosis, her debut studio album, was certified triple platinum and was supplemented by a further two platinum albums, Hilary Duff and Most Wanted. In 2007, she released her third studio album, Dignity, which was certified gold later than year and spawned singles "With Love" — her highest charting US single to date — and "Stranger". Best of Hilary Duff, a compilation of her greatest hits, was released in the last quarter of 2008 producing her a third #1 on Billboard's Hot Dance Club Songs with the single "Reach Out". Duff has sold over thirteen million records worldwide; her contributions to the music industry have gained her commercial and critical success worldwide while Billboard ranked her the 69th Artist of the 2000s decade.
Branching into the fashion industry, Duff has also launched her own clothing lines, Stuff by Hilary Duff and Femme for DKNY Jeans, and two exclusive perfume collections with Elizabeth Arden as well as having been signed on to modelling agency IMG Models. Other business ventures include writing a young adult novel Elixir and being accredited as an executive producer for According to Greta and a producer for the films Material Girls and Beauty & the Briefcase.