Keywords are important to SEO, but links also can help you a lot in SEO too. Generally, hypertext is like you link to the others’ sites while the others' sites link back to you. It's important that your site is being linked from the others' site.

Increase the exposure of your site to search engines!

Usually, search engines crawl from a site to a site, which are interconnected with links. So, if you get more links from the outer source to yours, this might help your site to be more easily crawled by search engines. If you do not have any links from any outer sources, then search engines might take times to crawl on your site. I guess you should know how important links can be.

Well, it’s still possible for you to stand still in the first page without building backlinks in the olden days. However, if you think it's just enough to optimize keywords and get your site onto the top ranking in these days, then you're wrong. In this competitive market, billions of sites are actively available. So, make use of links. Links can help you a lot in SEO. If many sites were linking to yours, then search engines will be much easier to crawl on your site.

Serve as a bridge

Links can be considered as a 'bridge' which is linking both sites. If you exchange links with some blogs/sites from your niche (it's better to be same niche as its relevancy), this bring some traffic to your site while you may bring some traffic to them too. It's a reciprocal act—— sharing traffics. Well, the wise man once adages that sharing is caring. Well, there are some facts that you must know. The statement 'Sharing is caring' isn't wrong sometimes, however, if you share with sites that are low-repute, like link farm, then this will not help you in getting higher ranking but eventually make thing worst. Well, I'll discuss some details later time!