Student by day and developer by night. I was born in 1989, started programming about 14 years later and haven't stopped since.
A good design is of vital importance for a website. Without it, it looks amateuristic and visitors will leave as soon as they get the chance (which is, let's face it, immediately in almost every case). With a good design your visitors will stay longer and better interaction will increase the engagement of those visitors.
But a good design is not all, just like a beautiful car is worth nothing when it's engine is one from a lawnmower. Ensuring your site is fast and responsive is as important as a good design.