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.
Recommend content is advisable for E-commerce bloggers. For e.g. Recommended books. A buyer will want to know what more is there in store for him/her.
Add your personality - If you are writing on a particular topic, there are a number of people who will be writing on the same topic. So you need to add that specialty to your blog to make it look different and to allow your readers to take away something that the others are not offering.