Most experienced bloggers will tell you that accuracy and consistency, along with quality are the keys to successful blogging and yet, that's just a start of what you need to know.
Your blog posts must be relevant to your readership and your posts must be in line with what they expect.
If you post too many irrelevant articles on your blog from your reader's point of view, not yours, then you will lose subscribes and your reader's interest.
Still, you can have accurate information that is well-written with a nice use of white space, a few pictures in each post, but if it is boring do not expect much traffic and the traffic you do get, do not expect them to stay long or subscribe.
Worse, if you post a lot of boring content, you will turn off even those who are very interested in your niche; remember these are suppose to be your target blog readers.
Some bloggers who have lots of knowledge and are extremely well-versed in their subject matter will inadvertently dump all the information on their blog too quickly, overwhelming their readership before they even develop a substantial following.
You must develop your readership and keep them interested with relevant material and deliver it in a fun way.
Does this mean that blogging is both an art and a science? Yes, that is basically what I am trying to convey here.
Now then, remember not to over post boring content.
Always consider your readers, subscribers and their interests and deliver the content in an exciting way.