Complex sentence: It pioneered a popularist form of articles, with an editorialship agenda aimed at the growing literate working-class, within twelve months was selling 4,000 copies per week to its local audience.
Split into simpler sentences: It pioneered a popularist form of articles, with an editorialship agenda aimed at the growing literate working-class. Within twelve months it was selling 4,000 copies per week to its local audience.