First, it depends on the quality of social channel and how well do you manage it.

In very simple, general way:
It does provide leads: some businesses keep up mainly on the leads social channels provide them. 

Think of a lead caught not by the link in the description of the company, but by the links you provide sharing common interests, stories. Bringing news and photos. And when everybody begins to listen to You (because of Your interesting, compelling, common interest with target audience content), You include a link to Yourself – and everybody do click it. 

With awareness we apply the same. Since everybody sees how their friends interact with what company. It’s becoming more viral. And friends acts in the way their friends do.

Conclusion: it provides leads and word of mouth. You engage with people, and they do bring other people. Keep working upon well content.

Thank you @tomas-slimas and @annfurnivall for giving me ome further information. Would you say companies that don’t have blogs to post their own content on are missing out on the possible “conversion” opportunities than the ones that have them? Thus giving a direct link back to their website for a possible conversion.

@trentjordan10

I would say if you don’t have a blog you are missing out yes. Social media like FB and Twitter etc are only 2 possible channels of advertising your product or service – and they are not the greatest. I think the idea is to reach as much of your target audience as possible and so by combining all of these media channels increases your conversion – abiity. Blogs are good, professional-looking, hubs to tie everything together and these days much more reliable and measurable than just one or two social media channels. If any of that makes sense. Yes to the blog thing is my point.