What Situations Would Benefit From UX Design? Link
Saying that all Web systems would benefit from a solid evaluation and design of the user experience is easy; arguing against it is hard if you care about user-centered design at all. But we don’t live in a perfect world, and we don’t have unlimited resources. Thus, we must prioritize and identify the areas that stand to gain the most from UX design and UX designers.
COMPLEX SYSTEMS LINK
The more complex the system, the more involved will the planning and architecture have to be for it. While investing in a full-blown multi-member UX study for a simple static website seems excessive, multi-faceted websites, interaction-rich Web applications and e-commerce websites stand to benefit a lot from UX design.