Some good info here.
Blogging has easily been the biggest factor in improving our sites SEO and overall PageRank. Most people search for answers to their questions or problems – not to buy a product.
But once you get the SEO juice and people are coming to your blog, you actually need a way to monetize them. We tried first by simply including CTAs to our products, but that hardly works unless your blog post is about your products. Instead, we've gotten great results by encouraging newsletter signups and ebook downloads to move them into a nice drip email campaign and into customers over time.
My recent post Participatory Posts and Gamification: 5 Ways to Increase Social Engagement on Facebook