One of the ways I save myself money when shopping online is pretty simple: I put a bunch of stuff in my online cart that I want, then immediately close the window and don’t return. Facebook is going after people like me with its rollout of dynamic ads on Instagram, which will be targeted at shoppers who browse online but don’t pull the trigger when it comes to actually buying items.

You may already have noticed these dynamic ads showing up on Facebook, featuring items you left behind in your online shopping cart. The social network is now extending the ad program to Instagram, and looping in travel-based targeting as well.

Basically, the ads work by tracking your internet browsing and app usage history, then show you ads based on what you’ve looked at. That’s great for advertisers bent on selling you stuff, of course — Facebook reported that more than 2.5 billion items were featured using dynamic ads in the past four months — but it may feel kind of… icky to others.

Those others include Snapchat CEO Evan Spiegel, who has called the ads “creepy” and invasive, and said his company won’t use them.

“We’re going to stay away from building really extensive profiles on people,” Spiegel told AdWeek last summer (h/t Re/code). “We have a really big business here that also respects the privacy of people who use Snapchat.”

Want more consumer news? Visit our parent organization, Consumer Reports, for the latest on scams, recalls, and other consumer issues.