With work and effort, I believe that the path towards a custom CMS serving as the foundation for almost all of a software producer's web projects can be useful, improving the organisation's productivity and competitiveness.
However different websites may be, they have much in common. Content editors increasingly want familiar resources such as article management, advertising, SEO, multimedia galleries, videos, forums and shops. These can be encapsulated in components and reused for different clients. This makes software production much more efficient, gives clients a more complete product, and allows effort to focus on their business model rather than on administering their website.
