A great blog strategy suggested at ProBlogger is to add authors to your blog.

Why are more authors better for your blog?

1. It gives you increased content volume and allows you to take a blogging break. If you want your blog to take off, you need to consistently post a lot. It’s a hard task to take on alone. And if you want to go away for a weekend, it is also difficult indeed. Having more authors = more content and the ability to take a break without losing post frequency.
2. You can get people to blog free in some areas. If you want to really take off, paid bloggers are also a good option. We currently offer this service.
3. Greater word of mouth. Having more bloggers means having more networks to spread the news. Most bloggers of this type will post to many blogs, cross link, and spread news to their associates.

From my experience, I think more authors is also a good strategy to retain your readers. It gives them multiple perspectives on a topic, but also opens them up to different topic segments.

For example, this blog covers many how to’s for blogging. I may talk on aspects such as writing, reasons to blog, etc, but Ianiv will be providing great insight on the technical side: how to set up your blog, how to customize it, and news that would appeal to developers in the blogging world. On one hand, this gives us a better chance of reaching and appealing to more readers overall, but it also gives some insight of the overall blogging perspective to all our readers. Something we think is very valuable.