I too am an advertising genius. During my spare time of not doing advertising, I dabble in marketing. I'm also pretty good at that too. So take my word for it, I know what is happening and what is not haps (an industry term).
I will now list in numbered bullet form what I know is going on with these Instagram (or "IG" for peeps in the industry) models:
1) Traditional modelling is dead. No more can a Kate Moss be plucked off the streets. Models are flocking to IG to be discovered.
2) They're not real models unless they get paid. End of debate. Let me go on, some models don't get paid, some models do. The ones who do get paid are the real models.
3) Prostitution is extensive. It's amazing what these women will do to be discovered. Most are giving away their bodies and letting men do anything to them for a box of protein bars. I have seen lower, but that was many many decades ago. We are almost at peak rock bottom for what women will do to get noticed.
4) Even the famous ones don't get paid that well. Basically IG is an advertiser's dream! What we pay accounts with 100k to 1m followers for what they do in return, is still at least the equivalent of 1% of minimum wage! Take advantage of this while you can. Who knows how long this golden era will last?
That is just a little bit of what I know. But it's a lot more factual than the other marketing commenters on here.