For most bloggers the biggest challenge is to gain and keep readers. We are all working to gain the attention of as many pairs of eyes as we possibly can. It’s silly to think we can gain the interest of every person that should happen upon your blog. But for the ones that do come and are interested in what we blog about we surely want to win them over and gain their trust.
With that said, lets talk about some of the things you could and should do to win and keep readers.
Pick your topic and stay on it – As I mentioned earlier it is impossible to gain everyone as a reader. But everyone has interests so to gain as many readers as possible pick your niche topic and stay on it. If you have a blog that is about Health and Fitness and you start blogging about your morning commute or other off topic posts, people are going to start heading for the door. By staying on topic, your setting the tone and will come across as being more professional with your blog.
Set your schedule and stick with it – I don’t believe there is a magic number of posts you should publish per day or week so it is up to you to come up with a frequency and set your readers up with some expectations. If you start posting several times a day and all of a sudden you cut back to a couple times a week your readers will think your priorities have changed. If you do need o change your frequency you might want to put a note in the sidebar explaining the reason for the change. Your regulars will appreciate this and prevent them from abandoning you.
Be yourself – Just as readers are interested in your blogs topic they will also be interested in you. Your opinions and writing style will become very important to your readers. Think of a popular talk show host, now think of the things that make them well liked. Their voice, views, humor, and anything else that attracts people to them. So when your blogging be yourself. People like that.
Keep score – There are a lot of other things that you are going to find that help to gain readers. So while you are trying different things make sure you keep score. What I mean by keeping score, is monitor your stats. The number of unique visitors, total visitors, subscribers and anything else you like to use as a gauge for how many readers you have.
Do you have a favorite method for gaining readers? Leave a comment and share with the rest of us. Who knows it may help you gain another reader. 
I have been around Internet Marketing for a while, but only recently decided to start up my own blog and it is by no means ready yet, though live. So my comment is more on gaining rather than keeping.
What I have done to start gaining exposure is create a Twitter account and installed the Twitty Tunes extension for Firefox. Whenever I have a new post or found something interesting to share I would just click on my Twitty Tunes button and I would automatically post to Twitter. I have gained quite a few followers who have added themselves to my Twitter Feed. Just make sure your settings are so that your feed is public to other Twitterers.
Another cool idea is to install WordBook (if your using WordPress and are active on Facebook.) Every time you post it gets automatically added to your Facebook news feed. There are other similiar applications and plugins also available.