In the 21st century, a phenomenon occurred in the United States and the world. A mobile phone began appearing in nearly every pocket and every purse of every person old enough to own one. Never before in the history of technology had one device become the centerpiece of our lives.

The cellphone you own today is your digital DNA. If you grew up in Denver, but have since moved to Austin, you have probably continued to maintain that 303 area code number, despite the fact that you live in the 512 area code now. As long as you pay your bills, you will likely die with the same mobile phone number that you have today, regardless of where you move or how many different devices you own.

This is why SMS text message marketing has become the workhorse of mobile marketing. It is the pillar that holds up the mobile marketing building. If you can only do one thing in mobile marketing, it should be text message marketing.

With an opt-in database well in excess of 100,000 phone numbers, Ace Hardware is a company that is very active with SMS marketing. In a report in Mobile Commerce Daily, Ace Hardware pegged the lifetime value of each opt-in as $183.60! Think about what is it worth for your business to capture the phone number of a customer who opts in to your business database and says: "I want to receive your promotional messages."

The key to broadcast text message marketing is to send consumers messages that are of value. That may seem obvious, but here is why it is so important. There is a fine line between your best customer — somebody who likes your company to the point where they have asked to receive your advertising — and your worst customer — somebody whom you have sent so many messages to that they have opted out of your text message marketing advertising.

Here's how to ensure you are sending messages that are of value to your customers, while not sending too many messages that annoy them and cause them to opt out of your database.

Sometimes it is more difficult to write a short message than a long one. Such is the case with text messaging, when you have only 160 characters to work with in the United States and 136 in Canada.

Abbreviations

Abbreviations are acceptable in text message marketing. When text messaging first caught on, they were actually kind of hip and cool. That is no longer the case, however, as consumers are more likely to find them annoying.

Write your message as best as you can, shorten it as much as you need to, and then — and only then — should you start inserting abbreviated words.

Embedded links

Embedded links are actual URLs that are inserted into a text message. They are quite handy to the smartphone user, because he can simply touch them and proceed onto the World Wide Web to easily access the website.

The problem with embedded links is they can often be long and take up too many characters. There is an easy solution to this problem: Use some kind of URL shortener, such as a bit.ly link. It is free and will save valuable characters if the business does not care about the branding the actual URL offers.

Of course, it goes without saying that the link must go to a landing page or website that is properly optimized for mobile.

Tap-to-call

Same as with an embedded link, a business can also embed a phone number in an SMS message. It becomes an easy tap-to-call for the mobile user, who can simply touch the embedded phone number and make a call to the business or organization.

If the business wants to track the number of calls the SMS message directly generates and quantify the value of the messaging, a unique tracking phone number can be used.

Mobile coupons

Mobile couponing can be a valuable tool for SMS marketing. Usually, a mobile coupon is redeemed with something like "show text to receive 10 percent off."

Of course, it is possible that a consumer can transfer such a text message to a friend, who can then also use it. But a business should be happy about that, even though the friend may not be an opt-in member of the SMS service.

This actually happens quite often, as evidenced by some of the studies done by Dunkin' Donuts and Subway. Expect that up to 20 percent of those who redeem your mobile coupon may have received it via forwarding from another opt-in member.

Mobile coupons are most effective in garnering immediate business, therefore any mobile coupon should have an expiration date on it. A business must create a sense of urgency. In most cases, that expiration date should be a week or less.

If it is a "show text" kind of promotion, there is no way to stop the consumer from using it multiple times, so a business should limit the valid time period for the offer. A business can also do even shorter flash sales very cost effectively with SMS. It could offer significant discounts that need to be redeemed by 5 p.m. the same day.

Some business may use a unique promo code with every SMS offer. This allows the business's POS system to track the effectiveness of the campaign, and with larger companies, it is often the only way that the POS system will allow a discount.

Sweepstakes

Of all of the text message programs that you will do, a text-to-win contest will have the greatest amount of participation. Everybody wants to win something for free, and a text message sweepstakes (known as a competition in the U.K.) is an easy way to enter.

Many marketers make the mistake, however, of believing that simply entering a sweepstakes is means for a verifiable opt-in, but that is not the case. A business must still provide the opt-in requirements in the sweepstakes response message if that interactive text message has the intent of validating a new opt-in to the database.

Text message voting

"American Idol" made text message voting popular long before most Americans were texting. In fact, it gave rise to a much greater recognition of texting in general. Many live events on the national and local level use text message voting because it is a real-time gauge of public opinion.

Just like with sweepstakes, voting is a great way to gain more opt ins for your ongoing SMS marketing plans.

Weather-related promotions

Businesses can take advantage of weather situations by sending messages based on the upcoming weather. If it is unusually cold, it is a great time to promote winter gear or sell snow blowers.

Text message alerts

After the mass shooting tragedy at Virginia Tech in 2007, many universities clamored for a quick way to notify the campus in the case of an emergency. SMS messaging was a quick and obvious way to notify college students en masse. Emergency text message alerts were one of the early categories that produced significant revenues for shared short code providers.

Today, most universities don't contract directly with text messaging companies. Rather, they work with safety organizations that offer everything from alarm systems to multimedia messaging, but text messaging remains a part of that all-encompassing emergency notification system.

Alerts are also used for less critical situations. Real-time text message alerts are sent by businesses for office and store closings due to weather and other unanticipated emergencies. Youth sports leagues send them for cancellations and announcements.

Real-time alerts make sense, since the vast majority of text messages are read immediately upon receipt.