Blog and email marketing are completely two different things. There are two completely different ways to market something, whether it's a product or a service. You will search that just because someone may use email marketing to make an income, doesn't mean that they always use blog marketing.
Blog marketing is when you use a blog to promote a service or a product. If you will market the product or service so that it appeals to others, and something that they might want or need. Using a blog you can get the word out about the product you are using and let others know all about it. There are various ways to do this. It can be done as simple or as complicated as you want. For example, you can market your blogs by swap links with other blogs that are compatible with yours. You can also drop comments on other blogs that will in return you get more visitors and readers to your own blogs. Do not forget to update your blog as frequently as possible. That will make a tremendous brunt on your blog.
 

Email marketing is when someone uses an email to get the word out concerning a product or a service. Simply you would have your visitors sign up for newsletters, then send an email to out all of them that did so. However, you'll also find that email marketing is great for many other things. You can put offshoot links in your newsletters and hope that your readers will sign up under you and you'll acquire a commission for those things.
Marketing in a manner of way is pretty much coequal. You should know who is your audience and who wants what you are selling. Once you know this, the rest of like a piece of cake. Whether you are pursuing email marketing, affiliate marketing, or email marketing. Even if you are into marketing offline, the same will apply. You will need to know who wants what you have to sell and you have no problem while selling it.
Blog and email marketing are uniform in various ways, but also very different. When you are using a blog for marketing, you have to post what you are selling on the blog. But for email marketing, you can use an email to any attentive parties. When you use a website to people in your newsletters for email marketing, you should know that you are not sending spam, but something that they solicit from your site. If something that they asked to be sent when they sign up for a newsletter. Whereas if you are marketing a blog, you would do this much the same manner as you would a website, and get visitors to come to you.
Whichever you prefer, whether it is blog marketing or email marketing you can get the outcome that you want and that you are looking for. Just know that it takes time and persistence to achieve what you want. Patience is key to getting your blog out there to everyone interested in it.