I am hoping that someone here might be able to chime in with an opinion on whether using network blog posts are an effective way of promoting or gaining backlinks for a website be it Directory or otherwise. I guess there are two different types of blog posts too. Those that are spun and those that are duplicate.
You need to promote 365/24/7 and at all times if possible promote with unique content, and blog posts help too
I would recommend a single professionally run Blog only. Blog Networks are just spam according to me, with all being duplicate content its utter nonsense. Gives a boost in your technorati temporary and then is later washed away too. Go in for a blog which gives you something original, is stable and is promoted. Directory yes its good to submit to professional directories too.
Blogs help, not sure of the "network blog posts", but have had a blog in the backend of sites and definitely helps. Gotta work it though. Careful how you read the traffic. In my experaince, lots of bots. Not always as good in reality as looks on the surface. Spend time submitting your blog and your main site to any and every acceptable place you can. Other directories, directory list, forums, trade links, etc, etc Do not just rely on a blog.