One of the great ironies of the boom in cloud services is how it has brought digital brands and human customers closer together than ever before. Companies today can reach customers whenever or however they need to, with an array of easy-to-use, low-cost tactics. More than that, brands have the ability to use specific cloud-based tools — such as email notifications — to build invaluable customer loyalty at minimal cost.

Email notifications today are a more advanced breed than their predecessors from earlier eras. Unlike unwanted or repetitive marketing messages, which customers typically ignore, email notifications are explicitly tied to specific actions a user has taken with a site or app — and therefore perceived as highly relevant or valuable information they need to know. Security offers the clearest example of relevant communication: Customers can receive an automated email wherever they are (and on whatever device) about login attempts and password changes, or during broader crises like Dropbox’s password breach. “It’s a way to involve the customer and deputize them,” Mark Schwanhausser of Javelin Strategy & Research explained in a recent interview with Nasdaq.

Giving users more power and involvement is a win-win beyond just security. As all of our activities — work, social life, shopping, entertainment — are managed digitally, we’re in need of constant information from our chosen brands to keep track and manage our lives.

A central challenge for brands is to ensure that the communication is truly useful or relevant. This is where so many companies have erred in the past: With only limited tools to assess a customer’s desire for a particular marketing message (such as the tracking pixels that detect email opens), it was difficult to if a message was successful. Notifications today are backed by superior tracking technology, but more importantly, they are almost always created or chosen by customers themselves. Facebook and Instagram, for instance, offer a wide range of opt-in choices for either email or push notifications, which are then triggered automatically by status changes or new messages.

To be sure, many of these notifications could be seen as potential spam — all it takes is a customer changing their mind about a message they previously opted into. But this is rarely the case for well-designed messaging. SMS notifications are opened 98 percent of the time within five minutes, according to Nielsen: hardly an indication that users are exhausted by messaging. Similarly, 70 percent of smartphone users consider all push notifications useful. This is true despite a sometimes huge volume of notifications: Slack, a chat app for business, sends a push every time a highlighted word (such as your name) appears in group chats. Despite the appearance of a deluge, users simply swipe away or delete any notifications that are unwanted.

But while ephemeral, easy-to-dismiss notifications such as SMS and push are great for some purposes, they don’t suit many notifications. For higher priority messages, email is often the first and only choice, and for good reason. For one, it’s an absolutely ubiquitous, omnipresent technology: on phones, smartwatches, laptops, even the Amazon Echo. It’s also a secure platform, with every message transparently routed and authenticated, and significant user account protection across all the major email providers. Permanence is yet another strong point, with inbox search allowing records to be found in a snap, whether it’s a discount code the user dismissed at first sight or a vital flight confirmation.

Finally, email is the only notification platform built for bi-directional communication — allowing your notification to turn into a conversation.

No matter which notification platform brands choose to deploy, building trust with customers starts with involving customers in the process — in choosing notifications, and using this feedback loop to make constant improvements. Businesses that test a variety of opt-in notifications are better positioned to discover what their customers truly care about, and how to discover the right balance between communication and disruption. Over time, messages designed in cooperation with users become second nature to both the company and customer. It’s difficult to imagine life today without notifications about security, social activity, incoming shipments, promotions and more.

And that’s why users are growing to trust brands that use notifications: More than marketing or even customer service, good notifications offer utility value and fulfill a customer need. While traditional messaging often leaves users fatigued by useless inbox fodder, cloud services have opened the way to communication that truly matters.