Yes link-back really helps to grow a blog. It is always better to enable link-back feature in your blog site.
A link-back is just like a give and take policy. If you have shown interest in ln linking others' articles and link it in your blog, other person get notified about that and would be interested to visit your blog too. In operates just like commenting on somebody's article and get comment in return for your articles. Both of you will grow. And I think that is a good strategy to have more visitors for your website.
Link backs are pretty popular as it's more or less a gaurenteed way to get extra traffic to your site or blog, without having to spend a fortune.
It's basically what it says it is, you link an article, and that article or site links your blog or site, it's as simple as that. Obviously the amount of extra traffic you generate will depend on how popular the articles you link are, but you can get some good results just by doing this.
Online marketing and promotion is a give and take process. If you visit a blog, you will get visiotors, if you leave comments, you will receive comments, if you link the article, your article gets linked back. By linking other blogs and websites with your blog/websites, you are not just doing favor but also marketing your blog/website.
In a way it's a form of promoting yourself aswell as promoting others. The more your name (or site) is mentioned then obviously the more people will know about it, and that means there's more of a chance that they'll come and visit your site, generating traffic for you.
Backlinks help in exposing your site to the audience. Backlinks can redirect other site's visitors to your site, hence driving free traffic. Backlinks are a must if you want your campaigns to be successful. You should not only rely on backlinks to improve SEO.
Most people use backlinks for SEO and to move their website up the ranks in Google. However, I've always seen backlinks as a good way to generate traffic. If the links you are placing, say in a Facebook group, are relevant to the group or platform you are posting them in, then you should be able to get some decent traffic from posting the link. However, spamming the links everywhere on the web won't work. The links really need to be placed in areas where people would be looking for the info that the link leads to.