I run a travel agency site and don't have a blog. My site is well over 750 pages with over 500 products. 85% of my customers are one off visitors to my area and one off visitors to my site. A Blog would'nt change those figures much at all. Our website is also covered in pics of me and my family enjoying the things we sell, as well having many personal recommendations.
I'm flat out keeping on top of my ever changing content and rates as well as writing and spinning multiple articles daily, let alone writing a daily blog post.
And we do OK financially without that essential blog.