A business can't just set up new social media accounts and start selling, it has to build up a reputation and let potential customers know what it's all about first.
The first goal of social media is therefore Brand Awareness.
This is a wise move - if you're a small business, people outside your local area likely know nothing about you or your brand and need educating first. However, how do you move on from this stage to actually selling to your followers?
The next step is Engagement where you identify your potential customers and spend time in conversations with them. Ask questions, find out who they are and what they want from you, build relationships. Only then, can you start selling to them.
Now, you can either run a social media campaign to drive offline sales (if you have a local high street presence) and/or drive traffic to your website with the aim of converting these website visitors into sales. The best way to achieve this would be to use some advertising budget.