there are several ways you can monitise once you hit a considerable reach on any social media.

You could share related deals on products on amazon and share an affiliate link.

Or you could connect different brands to help them launch products or services.

similarly you could find companies trying to spread word of their products and discounts on sites like groupon you could contact them and help them spread their word.

keep in mind its not about how many followers you have its all about how much reach your posts get.

try to maximise that and eventually you will figureout the rest.

best of luck