Not everyone knows the term “retargeting ads” but practically everyone’s seen them in action. After you visit a website – let’s use Ed’s Eggrolls for our example – ads for Ed’s Eggrolls begin mysteriously showing up when you log onto Facebook or visit your favorite news website. It’s not a coincidence, and Ed’s not actually psychic and strategically pre-buying ad space in the areas he knows you’ll look; instead, what we have here is retargeting advertising in action.

[Tweet “Retargeting Ads are very powerful for capturing the ‘browse now, buy later’ shopper.”]

Retargeting advertising services are pretty straightforward. They make use of cookies (small pieces of data stored in your website visitor’s browser) to identify what websites you visit and what types of content you found most appealing on that website and then generate relevant advertising to be displayed on other websites and social media platforms you visit. In other words, if you spend a great deal of time reading about Pork Eggrolls on the Ed’s Eggrolls website, the ads you’ll see on other websites will very likely feature special savings on Ed’s Pork Eggrolls.

Retargeting ads have become a popular marketing tool because they’re effective. Whether they’re entirely and directly responsible for the sales spikes that occur after their use is a matter of some debate in the advertising industry, but for most retailers, the existence of a sales spike is more important than the cause. Retargeting ads keep a brand’s marketing message effectively in front of customers for an extended period of time: they’re very powerful for capturing the ‘browse now, buy later’ shopper.

But are retargeting ads right for every type of merchandise? Erin Sagin, writing for the Business 2 Community website, says maybe not. Some people may wish to keep their shopping history extremely private – and the first example she cites, for a website that facilitates extramarital affairs- explains why. In the same category of ‘maybe you’d better not’ she places engagement rings. After all, someone who’s about to pop the question might not want to have the surprise spoiled when their special someone glances at their computer.

I have to say I’m not so sure of the wisdom of this recommendation. It’s one of those perfect storm scenarios where many, many factors need to come together all at the same time to happen: our romantic web visitor must look only at engagement ring sites and no other websites that use retargeting advertising at all (Sorry, Ed’s Eggrolls!) AND that retargeter ad must display on the website at the exact moment the significant other happens to be looking AND it must capture their attention AND they must know that what they’re seeing is in fact a retargeter ad prompted by previous web browsing activity.

If all four of those factors line up perfectly – which is fairly unlikely – will the surprise be ruined? Or will someone that savvy probably already have a more than decent idea that their sweetheart is thinking about proposing? Having your store’s engagement ring be the one currently on display during any conversations that may happen at that point isn’t the worst thing that could happen for a jewelry retailer. If you’re not using retargeting advertising now, it’s time to start thinking about it.