Ad fraud is a plague on the industry, with some estimating that as much as 30% of advertising goes unseen by consumers or roughly 21,000 trillion ads. This year alone, fraudulent advertising is expected to cost businesses $23 billion, money that’s essentially wasted on bots and fraudsters. Unfortunately, fraud has become such a pervasive problem that many marketers just chalk it up to the cost of doing business. They even plan for it in their budgets, opting to take the lower-cost buy, knowing that nearly 20% of it could be wasted on fraud.

Of course, there’s plenty of technology out there aimed at helping to prevent buyers from falling victim to fraudsters, from whitelists to algorithms to verification databases, and reputable publishers take whatever steps they can to protect their properties.

But, relying on technology as the silver bullet clearly isn’t sufficient in combatting the issue at hand. Despite all of the “solutions,” fraud is still a huge problem.

The reason: fighting ad fraud is not just a battle of technologies, it’s a battle of wits between humans. There are people responsible for each fraudulent technology—criminals who have designed the system. And as we know from ransomware, digital espionage, browser hijacking, and other digital criminal activities, to defeat the genius of the human criminal, an equally smart, efficient, noncriminal human genius is required.

Read more: In-App Advertising Fraud: The Biggest Threats to Advertisers

While tech is certainly a viable weapon in the fight against fraud, it must be backed by a team with a smart strategy. Here are a few tips that can help make sure you’re buying placements that actually work:

Know what you’re buying, as opposed to buying blindly. Using blacklists is fine, but there are so many technologies and lists out there. Make sure you’re purchasing best-of-breed placements, and only buy into what you know to be good and safe, rather than simply trying to maximize volume by going after everything under the sun.

Don’t buy based solely on budget alone. Advertisers will often hesitate to move to a vendor who’s more diligent and stringent about the quality of their inventory because the price inevitably goes up. When vendors let a little fraud mix in, it brings the overall CPM pricing down. This looks better for the advertiser because they’re seemingly getting more for their money. But is it worth the cost if 10-20% of it is wasted on fraud? For example, you might spend $1k each with two vendors. With Vendor A, 20% of that went to fraud, so you’ve just wasted $200. With Vendor B, which offers much higher quality, you might spend more per placement, but all of it will go to quality ads rather than garbage. In fact, you could have spent just $800 and reached the same results. Overall, you get what you pay for and actually end up saving money by having it go toward guaranteed quality buys.

Understand the nuances of your audience. By becoming more granular in your targeting strategies, you can gain a much better grasp on how to best reach your intended audience, leading to better results and much less fraud. Let’s say your target is 25-40-year-old first-time mothers in the Midwest. That might sound specific, but it’s actually a very broad range. Instead, segment it even further, for example, moms who have visited your site looking for information versus moms who are ready to actually make a purchase. By segmenting based on behavior, and determining what type of creative, messaging, and language you need to reach them, you can target much more specifically and eliminate a large amount of fraud, as opposed to a more blanketed approach. Plus, this is the type of Personalization is what audiences are looking for. In a future world, we have a machine that will do this for you, but that’s decades away. Right now, you need a human who’s smart enough to work through this strategy and pinpoint exactly who you’re targeting, not just demographically, but behaviorally as well.

Partner with a vendor who has your best interests in mind. It’s one thing to subscribe to an algorithm or tool, but it’s an entirely different ballgame when you work with a vendor who can aggregate data from multiple algorithms and outlets, and couple that with the expertise to maximize the value of that intelligence. By working with a vendor who’s built long-term relationships with media companies, platforms, advertisers, agencies, and more, who brings deep proficiency to the table to address this complex problem, marketers and advertisers can dramatically reduce their risk of wasting money on fraud.

Having the right tools in place can certainly give you an advantage over fraudsters and help to reduce the amount you waste on ads that consumers never see. But, relying on technology is not the cure-all that some vendors would have you believe. When wielded by smart people with expertise and experience, those tools can become strategic weapons that dramatically reduce your risk of being scammed.

Read more: Beware: Ad Fraud is Not a Harmless Crime