The theory behind regular updates on blog content hinges on the idea that it provides your readers with something new to look forward to. When your visitors come to your website and they don't see fresh and updated content, they will probably never visit again (or not as often as you'd like for them to). But if you have something new to offer, then this will keep their interest up - resulting in a higher likelihood of return visit.
Based on my own experience, I try to maintain 3-4 blog posts per week. I do have a full-time job and keeping up with daily posts is something that I simply cannot handle. However, if you work on your blog full-time, then you should consider daily posting to attain maximum traffic and growth. Just make sure that you can handle the writing and marketing of your posts. After all, your job as a blogger does not end with writing fresh content - you have to market and promote the content, too.
If you are looking to maintain a steady growth in traffic and followers, posting once per day or posting 3-4 times a week should suffice. However, you should not lose sight on the main goal for posting - enticing your readers and providing them with fresh information to digest. Are you compromising quality of your posts for the sake of publishing a new post? If that is the case, then you might want to re-think your strategy of posting frequently. Also, what you do off your site is of equal importance to what you do on your site.
Use your own judgment when determining the frequency of updating content on your website. Here are parameters you should use to determine your blog plan: 1) the availability of time, 2) your blogging goals, and 3) your off-site marketing plan.
How often do you update content on your blog?