I have subscribed to some email newsletters on various blogs. Usually I have been lured to join these lists by some sort of promise by the author. They promise me free e-books or exclusive content. They promise me something special.
When I unsubscribe, it's because the emails I receive don't deliver the promise. Yes, I got the e-book or the to do -list, but all the following emails only told me when your blog had been updated.
This is what most of these bloggers do with their email campaigns: They use it to inform me when their blog has been updated. I most likely have already liked your page on Facebook, I'm already following you on Twitter and perhaps even subscribed to your blog with a feedreader.
Therefore sending me an email telling you just wrote a new blog post or created a new video feels useless. I don't get anything from it.
The best email newsletters give me something different. They make me feel special, cause I subscribed for the newsletter. I gave you my email address and in return I want something that not everyone gets just by visiting your website.
In order to make me subscribe you need to promise me I will get something else. Something not everyone will get. Something beyond the gift. And then you need to deliver the promise, instead of sending me notices about things I can find out by coming to your site or following you on Twitter.