There are several excellent social networking platforms that entice user engagement, but your blog is the most important.  Unlike other external networks, such as Facebook & Twitter, a self-hosted blog gives you total control over your content, media, branding, and anayltics.  It is your social media home base.  Below are 5 great reasons you should have a corporate blog:

1.  Having fresh content will help with Search Engine Optimization, as google awards web sites that have up to date, relevant content.

2.  Industry specific articles will establish you as a knowledgeable information leader.

3.  Articles can generate great discussions between you and your customers, humanizing your brand and establishing trust.

4.  Frequent readers become "Brand Evangelists".

5.  By placing your readers on a level playing field you are allowing yourself to learn from them, which is the whole point of engaging with them in the first place.