I spent last week in Glasgow and London, with a UK SIM card temporarily in my phone. As part of my daily routine of checking Twitter, I learned that many social media advertisers and agencies have forgotten how to use Boolean operators, specifically NOT.

I saw a huge array of poorly-targeted “audiences” used by UK companies within 48 hours of activating my Three phone number. And notice that it took a full 48 hours for the magical, real-time capabilities of adtech to start wasting advertiser dollars. Consider that the next time you hear “real-time” in some pitch from a middleman or clueless agency.

For want of a Boolean operator, lots of advertiser dollars are being wasted. Some examples:

Example 1: Nescafe UK

The T&Cs for this promotion require that the winner be a resident of the UK to qualify. Yet the audience selection allowed the ad to be shown to a phone number that was just lit up and to a Twitter profile which places the owner’s location in Centreville, VA and Utica, NY. Definitely not Glasgow.

The selection could have been fixed pretty easily. In the process of developing the audience, the person running the selection could have used the Boolean NOT to remove anybody with a US location (per Twitter’s user profiles).

Example 2: BT Sport

This could have been fixed by an easy Boolean AND. Just look for some level of interest in soccer, which you’ll never find in any profile that Twitter or anybody else has on me.

You might say that it’s possible that this ad was just targeted too broadly. Maybe they were trying to get U.S. soccer fans and just cast too wide a net. Fair enough–we’ve all made that mistake.

But I know that wasn’t the case because the URL hidden here (because BT Sport prefers using hieroglyphics to English) links to a UK site. If they were trying to reach Americans, the URL should take me to a BT Sport America site where presumably I could have figured out if the programming was available on my cable provider or how to view it otherwise.

Bonus Example: Slow Tech, With Santander Bank UK

While editing this post, I checked Twitter. My U.S. SIM card has been installed for about 12 hours now, and I’m still seeing UK-targeted ads, this one a premium video ad.

In this case, there’s not one, but two missing NOT operators. For the first NOT they should have suppressed US addresses in Twitter profiles. The second NOT should have been not to show the ad to a US telephone number.

Not very much money was lost by these particular advertisers because of these specific mis-targeted ads. But it makes me wonder how many other cases there are every day on social media where minor Boolean slip-ups are costing advertisers money. It also makes me wonder how the rush to increase reach and audience size has caused marketers to miss the basics of merge/purge logic during the select and suppress process.

There’s probably a lot being wasted. And Twitter, Facebook, and Google are never going to tell you how to tighten your suppressions.

Takeaway: Think of your audience creation process as a merge/purge*. Understand your select and suppress hierarchy. Know your Boolean logic. Don’t be fooled by “reach” and audience size. And win.

* Don’t know what a merge/purge is? I used to run some of the most complex and successful in the business. Call me.