For most brands, the product journey used to end at the point of sale. Today, the growing resale market is rewriting that story.

From high fashion to high-performance gear, limited edition spirits to collectable cosmetics, products are living longer lives - and showing up in new hands. The global resale market is expected to reach $350 billion by 2027, driven by growing consumer demand for circularity, sustainability, and access to premium goods.

But there’s one big challenge standing in the way of the second-hand economy: authenticity. When you buy products from a recognised retailer, you know you’re buying the real thing. However, checks and balances can be lacking with many resale sites – leaving consumers unsure what they’re getting.

Here’s 6 reasons why brands should consider authentication on their products, to unlock the resale market.

1) Counterfeits create more than financial issues

Let’s start with the obvious. Fake products are a real problem.

From spirits mixed with dangerous methanol to faulty chargers that fail safety checks, counterfeit goods aren’t just brand-damaging - they can be physically dangerous too.

In the primary market, retailers have trusted suppliers, meaning you can be sure that the product you’re buying complies with all the relevant safety regulations and should be safe to use. In addition to this, any product recalls will be easy to communicate.

However, when buying from Joe Bloggs on eBay, Vinted, or StockX,  that level of regulation is lost. In the secondary market, consumers take a leap of faith with every click. If a product’s digital identity doesn’t travel with it, neither does its protection.   

By embedding authentication at the product level, not just on the packaging, brands can extend that protection far beyond the original owner. Giving every consumer, whether first-hand or fifth, a way to verify that what they’ve bought is the real deal.

By investing in authentication, you’re saying to your consumers you care about their safety and money, regardless of who they bought it from.  

2) Authentication adds value to the product 

There’s a reason resale platforms have built their entire brand on verification. Provenance matters. If you can prove where an item came from, it’s worth more.

And this applies to brands too. Connected authentication turns your products into premium resale assets. Whether it’s a limited-edition bottle of whisky or a pair of rare trainers, verifying authenticity with a simple scan can turn “used” into “trusted” and command higher resale prices as a result (and higher resale prices, can mean higher initial prices).

More importantly, it keeps your brand reputation intact. Because when someone buys second-hand and has a bad experience with a counterfeit, they don’t blame the seller, they blame the brand. Authentication protects you from this.  

3) Gain new data from old products

Traditionally, resale is a black hole for brands. Once a product leaves the store, visibility on who owns it and how they’re using it, stops.

But with connected authentication, every scan tells a story. If a consumer verifies an item months or years after the original purchase and in a completely different location, you’re seeing proof of resale activity, and discovering where your products really go.

Over time, this data adds up to a new layer of customer intelligence. You can:  

• Spot which markets are hotbeds for resale 

• Identify which products have lasting value 

• Understand the lifecycle of your goods 

• Even combat grey market diversion by seeing if products end up somewhere they shouldn’t 

Authentication doesn’t just keep things real. It reveals what’s really happening for the other 99% of the product’s lifecycle.  

4) Create ongoing ownership experiences  

Here’s where it gets even more interesting; authentication can become part of the brand story.

When Levi’s launched its connected product programme with io.tt, we helped them design digital touchpoints that evolved over time, from original purchase to resale and beyond. One key feature? Ownership logging. Each new owner could scan the item and add their name, creating a running history of who wore it, where it went, and what it meant to them.

That’s not just tech. That’s emotion.

For resale buyers, this turns a second-hand product into a story worth sharing. For brands, it creates a community of engaged owners, even if they never shopped your site.

Authentication can be a gateway to ongoing digital experiences, from care tips to exclusive content to product registration. It brings resale buyers into the fold and gives every product a life worth living.  

5) Authentication fuels circularity and sustainability

If your brand talks about circularity, authentication backs it up. In order for products to be reused, resold, or recycled properly, their materials need to be identifiable.  That’s where connected packaging and digital product IDs come in. Authentication adds a layer of trust to resale and reuse, while also helping track product journeys for ESG reporting and regulatory compliance.

And as consumers grow more aware of greenwashing, authentication becomes proof of action, not just intention.  

6) Control grey markets, not just fight fakes

Counterfeits aren’t the only threat in resale. Unauthorised sellers, parallel imports, and grey market operators often move legitimate products through unofficial channels, creating pricing chaos and brand erosion.

Connected authentication gives brands a way to spot when and where this is happening. If a product is being authenticated outside its expected region, that’s a red flag. If multiple items are being scanned from the same location, it could indicate diversion.

This level of intelligence helps legal, sales, and compliance teams act fast and keep your products where they’re supposed to be.

Authentication made easy - for brands and buyers alike

As you can see, fighting counterfeits and adding a layer of verification goes far beyond savings from lost sales: it increases the value of your product, the level of trust in your brand, and unlocks post-purchase data. Meanwhile for your consumers, it’s saving them money, allowing them to recycle, and even keeping them safe.

One of the key barriers of authentication is that you need consumers to actively engage in the process. If you make it too complicated by asking people to enter their barcode number into a website to authenticate, then very few people will do it and you’ll get less data and insight as a result. That’s why it’s so key to make authentication, on product, and seamless, for the consumer.  

Our connected product platform, io.tt, generates cryptographic, unique NFC IDs and serialised QR codes that you can place on every product. These are secure, and easy to scale, giving you complete transparency across your portfolio. And for the consumer, all it requires is a simple tap or scan for them to instantly verify the authenticity of the product and see any other content such as circularity initiatives or recycling instructions you’ve added.  

Whether you're launching a resale programme, worried about fakes, or simply want to add value to your product long after purchase, get in touch and we can help.