Our primary use case for this product is as a portal. This includes B2B portals, B2C portals, and B2E portals. It is good for any of those use cases. We have some solutions which include all three of these portal types in one deployment. It has the capability of providing good functionality for these portal types in a variety of ways. If you just need a marketing website, I'm not sure that you need a solution like Liferay Digital. You can just use WordPress which will serve your purpose in most cases. But if you need a website that has user authentication and you want to have additional functionalities like document storage, processes, forms, and generally more sophistication, you need a solution like Liferay.
It is better to use a portal solution, and not only a content management system. That's my opinion.