It used to be that branding and shopper marketing followed a reliable formula for influencing shopper decisions. Create a stimulus (such as a television ad) to move people to the store and then stand out on the aisle with superior packaging so your brand is selected—the First Moment of Truth. The Second Moment of Truth comes when the shopper experiences the product and shares that experience.

What we’re finding now, as outlined in this short video from Google, is that it’s not a linear model anymore—it’s much more of a cycle. Today, when the consumer thinks about making a purchase, there’s another Moment of Truth that begins before they ever enter the store: the Zero Moment of Truth (ZMOT).

It’s here in this pre-shopping stage that consumers are reading reviews, searching for comparable items, talking to friends and finding deals or coupons. And, while this pre-shopping has been going on forever, today it’s becoming the most important stop on the shopper’s path to purchase. People consult on average more than 10 sources before making a buying decision—that’s more than double what it was just a couple of years ago.

The lines between each moment of truth are blurring because of mobile technology. Consumers are using their devices in the Zero Moment not only at home, but in the stores—right up to, and sometimes as a part of, the First Moment of Truth. Then, after purchasing the product, they’re sharing their experiences with social networks and taking and sharing photos of the product with their phone or tablet, making the mobile experience an integral part of the Second Moment of Truth.

What does that mean for brands and retailers? It means you need to be present. You don’t need to influence, you don’t need to make the hard sell or provide deep discounts, you don’t need to use the mobile platform as a brand battlefield. You just need to be there to give your already informed consumer the information he or she needs to feel comfortable making their decision. You need to be present with product information, you need to be present with deal information and you need to facilitate social interaction.

Simply being present on a shopper’s mobile phone and respecting the 1:1 nature of the mobile medium will encourage engagement and brand loyalty.

Being present all along the path to purchase is technically very easy. Resisting the temptation to use it to aggressively wrestle sales away from competitors or be intrusive with your advertising isn’t. But the medium isn’t about that—it’s about deepening the existing relationships between brand and consumer, and the Zero Moment of Truth presents an opportunity to do just that.