Content is one of the main things that affects the amount of loyal readers you can get. You can not just write about anything and in anyway and think that people will automatically like it. For loyal readers, your content must be fantastic, focused and posting intervals must be constant.
Fantastic Content
Content must be fantastic that captivates readers. The blog posts must provide value for the reader, so they will see that your site is worth a revisit. Unuseful content will simply push your readers away.
The most important thing is that you can write well. If you write well, then you can even turn a semi-good article idea to a golden post that is retweeted tens or even hundreds of times. Try always to maintain good quality in your articles and your readers will love your site.
Focused Content
Readers expect to get same type of content from your blog that they have gotten before. Do not let them down. Keep your blogs focus the same and do not divert too much. You can make small side tracks once in a while, but try to keep it to a minimum.
When your readers always get what they are looking for, they are pleased. Pleased readers will visit your blog again and again.
Posting Intervals
The idea about posting interval is that people will always have fresh new content when they come to your site. Try to post at least once a day, but for some sites every other day may be enough. I try to post everyday, hope it has been enough 
Conclusion
The main idea with content is that the reader is always pleased and you never let the reader down. The way to do it is to,
- Write great content
- Keep the content focused
- Have a regular posting interval
- Unique Post
Focus is main point when you consider keeping loyal readers. Many bloggers finding their blog focus point after several months of blogging. You can find what your blog should be focusing through chatting with blog readers, running ‘ask a question’ posts, analyzing your blog using Google analytics to know which posts has more readability etc.
Hi blggeri, I am new reader of your blog. Since two days reading your blog through RSS. Nice . Keep on writing.
Thanks for the comment Pascal. Great to hear that you also agree that keeping the focus is vital.
Blogging niche is the most important aspect of blogging. Selecting a niche which is not saturated is a smart move. ALso you have mentioned a nice points : Focused content and posting interval. I think posting interval really matters because a blog having irregular posting frequency lose its authority. Posting frequency also helps in getting nice rank in the blogosphere.
You are right about that. After people choose their niche, they should stick to it. Thanks for the comment