It depends on what you want to do with your Instagram accounts to make money. You can gain a lot of followers and sell posts to businesses that are on instagram.
Example: Instagram account dedicated to hair styles with 100K real followers, could sell post slots to hair salons/products/businesses that have advertise on instagram and are looking to gain more followers. Celebrities to it all the time.
Instagram is also great for selling items. That's what I'm currently doing. You can buy wholesale, take VERY good pictures of the items and post them to instagram. When people buy your product, have them send in a picture using or wearing it and also post them to your instagram with their username tagged to show others your product is selling.
Always remember, content is King =D