A revised version of this post appeared on MediaPost last month.

“Another password for yet another site!?” we lament as consumers.

While login details may eat up precious brain capacity (there’s an app for that!), there’s a reason that more and more brands are keeping their products and services behind locked doors. Leveraging single sign-on—that is, a single user log-in that works across desktop, mobile, and tablet—empowers marketers to build a more compelling, more differentiated offering, ultimately improving, not hindering, the customer experience.

Implementing this type of technology, however, doesn’t come without its complications. Let’s take a look at a few of the core challenges ahead for marketers looking to dive into the world of single sign-on… and the opportunities that success will bring.

Challenge #1: Getting customers on board

In order to get a customer—or, more difficult yet, a prospect—to share their information and take extra time to engage with your brand, there’s an element at the heart of this interaction: the customer value exchangeCustomers need to understand what they will get out of opening their time—and personal details—to you.

Let’s take a look at how a few of the most successful companies have used single sign-on to earn their customers’ trust and loyalty:

Groupon, one of the pioneers in the daily deals site phenomenon, attracts people to register by hinting at special offers and a tempting cash incentive. Offers are tailored to registered customers—a must for modern consumers who increasingly demand personalized experiences.

Starbucks has managed to build one of the most widely-adopted mobile payments applications—one that Paypal, Visa, and other payment companies have even tried to replicate.

How? By providing value to the customer:

  • No wallet necessary: easy way to hold your Starbucks gift card
  • Replenish funds: easier way to fill your gift card with ApplePay
  • Order ahead: easiest way to get your daily fix

In addition to the convenience, the ultimate driver of the Starbucks app’s widespread adoption is the loyalty program. Buy 11 drinks and get your 12th free: only available if you engage with the brand and use the application.

eBay offers new would-be buyers more subtle, but still compelling functionality: allowing you to follow auctions that matter to you. You will, of course, have to sign in or create an account for that privilege.

ESPN has figured out how to learn your favorite teams. They offer push notification alerts to keep up with what’s happening in real time… only available upon log-in.

Challenge #2: Implementing single sign-on technology

You’ve built a value proposition for the customer—they’ve created a single sign-on, granted you access to their data. Now what?

Enter the technology challenges.

It’s easy enough to have a customer record of what a logged-in user has done across multiple platforms—e.g., who has made a purchase from both desktop and mobile. But that’s just the start.

Here are a few single sign-on technology roadblocks and the best ways to tackle them:

Joining anonymous and post-login data

The best way to understand the entire path to purchase and customer lifecycle is to have a complete view. But this is only possible if the technical systems are in place to unite all of the online behavior of a customer, prior to them creating an account.

Example: you might have a customer on the web, who always logs in. They eventually download your app as well—but then they don’t log in for months, until they make their first mobile purchase. Since they were not logged in while they shopped, you’ll lose all the vital information that led them to the purchase unless you set out to collect it and tie it back to that customer’s account.

Using data for a differentiated experience

Collecting and understanding data is just the first step. Building the systems to use and deploy this data to delight the customer is where the magic starts to happen.

The personalized shopping app, Wish, which has raised more than $500M in venture capital so far, changes nearly everything about the customer’s shopping experience. It provides tailored emails and offers temporary, personalized sales on products you might like. But far simpler and more attainable is its ability to analyze the products you look at and adjust the app’s navigation categories accordingly.

While there are many uses of personalization, sometimes just the basics can make a huge impact.

Connecting data within all of your company’s systems

Lastly, tying together all the disparate systems within your organization can reap some of the benefits of single sign-on. Have a user who stopped viewing emails? Add them to an at-risk segment. Maybe offer that customer a win-back campaign the next time they open your application.

Perhaps most importantly of all, connecting data across systems will give you, the marketer, a holistic view into which of your efforts are bringing new, profitable customers—and which tactics need to be cut from your plan.