You would ask why I need to hire a professional to setup my blog when there are so many options available online. Customization - A business blog is different than a personal blog, your corporate blog needs to carry out your corporate image and be in sync with your website.
Corporate blogs may require additional features that may not be available with the standard blog setups online and may require that extra coding.
Some features that will include in your blog -
- Customized blog design
- User comments
- Permalink
- Trackbacks
- Monthly/daily/weekly/yearly archiving
- Comments active only on approval
- User management
- Posts management
- Multiple blogger levels

