8 million businesses using Instagram business profiles and more than 1 million monthly active Instagram advertisers on Instagram

Businesses that advertise on Instagram can access an Insights tab to view stats on their posts such as the number of times their posts have been saved, commented on, liked or viewed and learn more specifics about their followers, such as their location, gender and age. Instagram also gives businesses, especially those with tight marketing budgets, the chance to observe how their unpaid posts perform organically before deciding which creative to promote in an ad campaign.

Source: Instagram Hits 1 Million Advertisers, Fueled By Small Businesses