What niche is your blog because I suspect those people are interested in your niche. Promote offers to them through emails but don't do this in a way that you spam them or you won't effectively use the list to your advantage. My advice is to read some blog posts to get an idea how to use your list to get the most benefits out of it.
Harsh has a ton of blog posts on email marketing and a whole category dedicated to it. Please start reading blog posts then when you have a good idea how to use your list, create some emails.