Careful use of white space is a good thing. Don’t try to fill your web page with too much content or it will look cluttered and unprofessional.
White space refers to the areas in your design that do not contain content, including the larger spaces between design elements and the tiny spaces between letters. It doesn’t have to be white. – The Paper Mill Store
So white space, or negative space creates room to breathe and makes your content easier to read. The eye needs a place to rest and white space allows that.
You don’t get more value for money by using up every blank area on a page.
To see how some designers have used white space effectively, Creative Blog has some examples on their site.