A few days ago, I came across a tech news article mentioning that 33 years ago, a British engineer named Neil Papworth sent the world’s first SMS—“Merry Christmas”—from his computer. Since then, SMS quickly became a globally ubiquitous messaging tool.

Coincidentally, a few nights ago, my child found one of my long-unused backup phones wedged in the sofa. After plugging it in and turning it on, I was greeted with a barrage of dozens of messages. The vast majority of these were notifications from online services I had previously linked to that phone number, along with some marketing messages for online loans and promotional offers from carriers.

Undoubtedly, almost none of these messages came from a “person.”

This got me pondering several questions over the next few nights: Is there still any practical significance in downgrading a phone number to a “minimum-cost plan”? Why aren’t the automatic spam SMS blocking features working as they should? And aside from machine-generated messages, does SMS still hold any value for human communication?

Since opting for a “minimum-cost plan” is largely a personal choice based on individual considerations, I’ll focus here on two questions about SMS.

The Disappearing SMS

It was the moment my backup phone started incessantly beeping that made me suddenly realize a fact: It seems I haven’t actively sent an SMS to anyone in years.

But if we rewind twenty years, SMS was the most common formal means of communication aside from phone calls.

The reason I call SMS “formal” is that era marked a turning point in human communication methods.

What we learned as children—how to write letters, how to send telegrams—was well-preserved in the age of SMS.

On one hand, sending an SMS came with a cost. Even though it was cheaper than the 80-cent stamp required for a letter, considering the character limit, people rarely used SMS for casual chatting like they do with WeChat today. Instead, it was more about complete, one-off communication, often proofread multiple times before sending to avoid errors and the need for follow-ups.

The way we now send messages on WeChat—typing whatever comes to mind, sending a few words at a time—was unimaginable back then. Occasionally, couples exchanging large volumes of SMS during courtship were jokingly assumed to be “wealthy.”

On the other hand, due to the character limit, people grew accustomed to expressing themselves concisely. While not as brief as telegrams, it was undoubtedly more efficient than today’s casual communication.

Reading Liu Zhenyun’s One Sentence Is Worth Ten Thousand made me deeply reflect on how much time we spend on “ineffective communication.”

Things that haven’t been carefully considered are hastily shared on WeChat, only to be constantly revised, expanded, and supplemented. What could be said in one sentence often takes dozens or even hundreds of messages to convey.

Some WeChat groups are perpetually flooded with “999+” messages, rehashing the same topics day after day. People habitually forward information, engage in idle chatter, seek resonance, make new online acquaintances one day, find like-minded individuals the next, and some even join groups with the sole intention of picking fights.

Moreover, many people have hundreds or even thousands of WeChat friends—far more than their phone contacts. But much like SMS, most of these added friends may never contribute a single meaningful sentence to effective communication. Conversely, there are countless reasons to avoid communicating with them.

Everyone seems to be “seeking validation” online, looking for topics to discuss or people to chat with. Yet, even after exchanging ten thousand words, it’s hard to mask the spiritual loneliness.

Overall, this spiritual loneliness isn’t due to “not talking enough” but rather the opposite—it’s because words have become too light, too fast, and too cheap.

When the cost of communication is infinitely lowered, expression no longer bears any consequences.

A sentence can be retracted at any time, an opinion can be reversed in an instant, and an emotion can be washed away by new information within minutes.

In such an environment, SMS—a communication method with cost, boundaries, and a sense of delay—feels increasingly out of place.

Why Hasn’t SMS Been Phased Out?

From a technological advancement perspective, SMS as a communication method should have been phased out long ago.

It doesn’t support images or videos, lacks multi-user participation, incurs high costs for frequent conversations, and its sending and receiving speeds can’t match instant messaging tools like WeChat.

Even when carriers introduced “MMS” applications, almost no one used them in practice.

Yet, the reality is that SMS hasn’t disappeared. Instead, it has become more indispensable in certain scenarios.

The more important, official, or “must-not-fail” the information, the more likely it is to be sent via SMS.

Examples include verification codes, account balance reminders, security alerts, and government notifications.

These messages involve no interaction or emotion—they serve one purpose: to ensure the user sees them.

The reason is simple: SMS is arguably the only communication method that doesn’t rely on the user’s “active cooperation.”

As long as the phone number is active and the network is connected, SMS will be delivered.

It’s this “fallback attribute” that makes SMS the most trusted channel for platforms, institutions, and systems.

However, the problem is that once SMS is deemed the “guaranteed delivery channel,” it inevitably becomes abused.

Marketing messages, promotional offers, and loan advertisements have flooded this channel originally intended for “critical notifications.”

This mix of “legitimate and illegitimate” content has created an absurd situation in SMS usage:

Important information is sent via SMS, so users dare not block it entirely; yet, most SMS content is something users don’t want to see.

In daily life, many people set their phones to “whitelist” mode for calls, only answering those from contacts. But few dare to apply a whitelist to SMS because you never know which “important” messages might come from unknown numbers.

Does SMS Blocking Actually Work?

I checked the SMS app on my current phone.

In the inbox, there are 1,900 conversations, totaling around four to five thousand messages—all undoubtedly from numbers starting with 106.

In the “spam blocking” folder, there are only 350 messages.

Among these blocked messages, aside from some obvious online scam messages using “gibberish” from a few years ago, most of the recent ones are from banks, mobile carriers, and shopping websites.

Compared to the marketing messages that successfully reached the inbox, the default “online intelligent blocking” feature on this phone clearly has limited effectiveness.

I even noticed some bizarre blocking outcomes.

For example, monthly billing notifications from China Mobile: some months’ messages were blocked, while others weren’t.

Or work-related OA system reminders: most went to the inbox, but a few were blocked, possibly due to “keywords.” I only discovered this during my review.

Similarly, messages from certain merchants on shopping platforms: some merchants had all their SMS blocked, while others had none blocked at all.

This “mysterious blocking” pattern further erodes user trust in SMS.

More importantly, the current approach to SMS blocking presents a new paradox:

To successfully block messages, the system must read, parse, and even analyze the content of the SMS. Yet, SMS carries a significant amount of highly sensitive information.

Particularly concerning is that this blocking is explicitly disclosed to users.

In other words, users are fully aware that their SMS messages are being read by the phone’s operating system, the manufacturer, or the carrier. Under such circumstances, who would want to send private information via SMS?

It’s worth noting that while researching SMS blocking over the past few days, I had an even more “uncomfortable” concern.

I wondered whether the current SMS blocking process—where some marketing messages reach users while others are blocked—might hide another form of “unfairness.”

Specifically, whether “blocking rules” could be turned into a business: Messages from paying senders aren’t blocked, while those from non-paying senders are.

After all, under the so-called “internet mindset,” many platforms have a history of such “misconduct”: as long as you pay, any information can be sent and even prioritized in search results, leading to end-user deception.

Of course, given the national-level governance of SMS, I believe blatantly “illegal information” would struggle to pass carrier review rules. However, there’s still a long way to go in managing general “marketing” spam messages.