To increase a following on Instagram you can export a list of customer phone numbers and contact info from your database or CRM (as a custom .CSV file) then import them as contacts into a Gmail account. Then, import those phone numbers and contact info from Gmail into a smartphone and log into your Instagram account. Then, make use of Instagram’s “follow all contacts” feature, which will go looking for any of them on Instagram and then you can select them and follow them.
This would, naturally, need to be done prior to any GDPR legislation taking effect - so do it soon.
Ya can thank me later.