If you want to succeed at social media marketing, you have to understand one important thing. It's not about selling, it's about giving. And one of the best marketing books I've ever read, Jab, Jab, Jab, Right Hook, Gary Vaynerchuk stresses this point, give value, give more value and give an even more value.
Before you ask a client for sale on social media, you have to be building the trust. You can't just be expecting to post one post on social media and expect the sales to start coming in. Start giving value, start caring about the client and then ask for a sale.
Too many people make a mistake that they first jump in and try to make a sale on social media without building trust. Again, focus on building trust and credibility on social media and then the sales will follow.