Here are just a few of the rules that advertisers have to follow before they’ll be allowed to run a campaign:
Clients are not allowed to repurpose images they previously used elsewhere, in other ads for instance. No heavy use of image filters. No text is allowed on ad imagery in Instagram. No gimmicks! Ads should capture “moments,” not products. Ads must not simply be a product shot, in other words.
Instagram is working hard to not allow its photo community to be polluted by rogue advertisers.