The Jewish women's site
Don't ask me how we got there, but one of the first places the Big Girls Bras ad appeared was on a blog that discussed Jewish women's issues. This article, as you can see from the image, dealt partly with criticizing women because of their clothes, and it also contains the less than desirable term "slutwalk" in the headline. That's not a term any brand wants to be associated with.
What went wrong: When a cookie is dropped, the user gets placed in a bucket and classified as in-market to buy a brassiere, whether that consumer is female or male. The brand knows we visited its site, so it's very likely to buy impressions for us again. With this site, the ad-buying platform likely saw a page with content that appealed to women and felt it was appropriate context for the ad.
How to prevent it: Whether you're using standard retargeting to get site visitors to return to your site or buying intenders via a real-time bidding (RTB) platform, set your controls to weed out inappropriate terms and language. Women's interest sites are great places to advertise women's clothing, but advertisers have to make sure they get appropriate placements.