Newsletter: Newsletter is a great way to keep your audience glued on to all that is happening on your blog. It is best way to know who your loyal audience is.
Tutorials: For Business Blogs, have tutorials that teach your customers how to use the product/service, what are the features of the product/service and keep your customer views open for them to read.
Image speak - A lot of bloggers tend to ignore this, but the images on your blog speak a lot for what you write. Use good quality images and make sure they express your written stuff in utmost simplicity yet precision.