The best way to grow and strengthen your audience is to create high quality, on-brand content that people want to see in their Instagram feed. Creating strong content also increases the likelihood that your account will be discovered by non-followers from Search & Explore or Activity, where people can see posts that their followers have liked.
You can also grow your audience by making Instagram part of your day-to-day business and marketing. For example:
Post a sign at your retail locations with your Instagram account, or share it in communications like emails and postcards
Mention your account in the press
Announce your Instagram account on other platforms like Facebook or Twitter with a link to your account, or provide a link on the homepage of your website