Your smartphone is an ideal shopping tool — always with you and armed with a rear camera that captures things you might want to buy. Now imagine its front camera looking back at you, judging your reaction to what you’re seeing and taking your smile as a cue to urge you to make a purchase. That’s the innovation behind NexTech’s latest “sentiment-based technology solution” for its Try-It-On retail augmented reality platform, thanks to AI provided by Microsoft Azure.

If it sounds a little creepy, that’s probably because AI is learning to do what human salespeople have done for generations: gauge a customer’s sentiment and capitalize on it to make a sale. The difference is that NexTech is making facial recognition and analysis possible within retailers’ augmented reality apps and websites, rather than limiting it to physical stores.

While you’re virtually trying on a 3D-rendered article of clothing or looking at a 360-degree view of a product,¬†NexTech uses a device’s camera to live-sample your facial expression and then offer on-screen prompts based on what Azure’s AI “sees.” A positive reaction might conjure up an “add to cart” prompt, while a negative reaction could suggest an alternative option that might be more to your liking. Retailers can customize the prompts and sentiments to their needs.

“It’s a similar effect to the attentiveness of an in-store employee trying to persuade the customer to buy something they are trying on,” explained NexTech CEO Evan Gappelberg, “except now it can be done digitally, both at the point of purchase and through retargeting at a later time.” In other words, if you leave the retailer’s app or site, it can email you later with a deal and know how you responded when you come back.

And the AI-powered insights can be improved, he suggested. “Retailers using this technology will be able to convert customers at a higher rate by having insights into what they like and what they don’t and refining what’s marketed to them, creating the customized experience consumers desire to empower their purchasing decisions.”

In some cultures, face-to-face haggling over prices is a daily occurance, with strategically timed smiles, stern faces, and frowns serving as negotiating techniques. But as shopping continues to move online, this sort of personalized element could get lost. As NexTech points out, 100 million customers are expected to use AR in some form as they shop by 2020, so solutions like this could make their experiences more sentiment-responsive.

NexTech’s AR/AI solution is available to online retailers for $79 per month and promises a universal 3D shopping solution that can be implemented¬†with “just a few lines of embed code.” The software integrates with Shopify, WordPress, and Magneto.