No leads = no customers. The internet is a massive place and may seem impossible to know where to find potential customers. Some quality leads can come from: email, organic social, paid social, programmatic, SEO, SEM, PPC. In our experience google and search engine optimization drives the best leads and quite faster than social. Social channels gets you in front of an audience not actively searching, but potentially close to making a buying decision.
You should be investing time and efforts into social media channels if you want to connect with your target audiences. Social media users are in the millions and growing. Find the right social channel for your business and create your niche in the market - your customers will follow.
The end goal of lead generation should always be to convert leads into customers during their journey. Invest your efforts into finding the right channels to allocate your target audience, leverage customer feedback, pay close attention to your data and metrics to see which channels are delivering the highest conversion rates.