Native advertising has been growing since 2009 so quietly you may not have noticed—and that’s the point. Native advertising in fancy-speak is “a form of online advertising that matches the form and function of the platform on which it appears.”

Basically, it’s the advertising version of “Where’s Waldo?”: it’s definitely there in plain site, you know it’s there, but it blends in with its surroundings. And just like Where’s Waldo, viewers are bizarrely addicted to the hunt.

You’ve consumed these ads in disguise by the dozens (surprise!) through media like Facebook, Spotify, and Buzzfeed. You’ve poured over them because they’re articles and images that actually pique your interest. Once reading, there’s not a mention of “buy” or “free trial,” in sight. Instead, The only clue that they’re paid content appears through words like “promoted” and “sponsored” tucked into the subheading or a brand shout-out in the footer. Oftentimes, the brand’s touch is so subtle that audiences don’t realize they’re consuming an advertisement.

The goal isn’t direct sales; it’s building trust. Through creative storytelling, sponsored posts engage consumers with material that may or may not be on-strategy for the brand. By devoting time and attention to content of interest, consumers share good vibes with the brand when making decisions long after they’ve clicked out of their web browser.

Keep these three things in mind when you delve into native territory:

1. Be very, very clear it’s sponsored content. Though subtlety is key, people as a general rule don’t like feeling duped. Keep the content relevant and your brand presence evident.
2. Don’t stretch the truth. Because viewers may not realize the thought piece they’re reading is sponsored content, they’re more likely to take your advertisement as fact and not opinion. News source The Atlantic came under fire when they allowed a native post by the Church of Scientology to spout puffed-up claims under the guise of “news.”

Make sure your content aligns with the tone and flow of the publishing website. A testimonial about an insurance company on a blog about organic foods will pop—and not in the good way. Ad content that doesn’t mesh with its host site defeats the purpose of native advertising.