How can a firm form a sustainable competitive advantage and maximize the revenues and profits?

Outstanding products, with excellent management of products lifecycle + preparing more outstanding products  to be ready to be distributed when the current ones get expired (Boston Matrix Strategy for example) + deep understanding of clients needs, demands, and behaviours for effective transformation of those needs to products & services + market & industry (including competitors) contineous & effective mind+ continueing innovation & development

Either through price or through product/service differentiation.It may not be a sustainable option as other firms tend to imitate and one needs to constantly innovate to find new ways to stay ahead of the competition.

Through innovative marketing and remarkable customer service.