Welcome to the tough world of link building. Here are some specific insights from my end:
1. I typically see about 1 response to every 15 - 20 requests. If its a straight-up one way link request, its much worse. More like 1 response in 50 requests.
2. For blogging specifically, I have seen success in two ways: blog rolls and sponsored content. Social/blogs are a bit different than websites. Interlinking is viewed a little better, so I love to include the other blog first in my own "blog roll", then reach out to them, let them know "you added them to your blog, you like what they have and are following them. Would they include your blog too on their roll". then throw out a useful comment or two on their blog, and usually the combination of those two things gets you a link.
I will also sometime ask relevant blogs to "sponsor a post" for them. Basically, write a nice article or post, and pay them $50 to post it on their site. You just say you want to get the word out to "their audience", and $50 is not bad for little effort on their end. Of course your link is in the post 
hope that helps.