Blogs and social media communication tools such as Facebook and Twitter are only as effective as you make them.  If your company has a blog, you must blog regularly and consistently.  One or two blogs a month won't help your business garner an audience or attract potential new business.  Of course, your blog communications have to be interesting and unique.  If you're not communicating regularly with your target audience, you'll lose them quickly.  There are simply too many websites and blogs producing useful information regularly.   I've seen it often enough that companies will create a blog or a website and then let it sit for months without adding fresh content.  This is a waste of money and time.  If you're going to jump in and commit to online marketing through a website, blog, or any form of social media, do it with discipline and consistency.  Your marketing efforts will pay off in the long run.