Instagram

#1
Since that is not the case, then chances are, they have not heard your pitch. Take them off of the social media channel with a call to action. Direct them to a 'profit location'. Put in place a variable marketing campaign and talk to them again, and again, and again.

Analysis & Optimization

Finally, analysis & optimization must be a large part of your Instagram strategy. There are two different analysis techniques you need to understand. Quantitative (measurement) and Qualitative (non-measurement).

Quantitative

Here is where you can measure the engagement with Instagram each image / post. Create (or use an analysis app) where you can calculate the interaction from each post.
Your desired measurement is going to be the number of clicks to your link in profile.

You will want to measure how many of those clicks converted to a lead (they gave you an email). Quantitative measurement shows you revenue potential. When each of those leads follows your marketing campaign (tip #4) you have a good starting point.