SMS marketing is a huge growth area for businesses of all sizes, and it's not hard to see why. It's cheap (texts cost just a few pence, especially if bought in bulk), and it's easy to track return on investment.

But most of all, SMS marketing is direct and personal. Look at it this way: If you send your customers a marketing email, it's probably just one of dozens they'll receive that day. Chances are that only a few of them will open your email, meaning you'd need to send it to thousands of potential customers to make the exercise worthwhile.

That's not the case with SMS. Most people receive relatively few text messages from businesses (we'll look at why in a moment), and it's very hard to ignore a text when it arrives.

If you send 10,000 emails in a marketing campaign, only a few hundred will likely be read—even if you have a brilliant headline, great copy, and a must-have offer. But if you text 10,000 people, you can be pretty sure that nearly all your recipients will read your message. If your conversion rate for SMS marketing is close to your conversion rate for emails, that translates to 10 or 20 times as much business.

Interested? Before you start collecting customers' mobile numbers for SMS marketing, you need three essentials in place: a great offer, the right technology, and most important—your customers' trust.

A Question of Trust

There's a reason most people don't get as many marketing texts as they get marketing emails. They see their phone numbers as more personal and more valuable than their email addresses, so they are more careful about whom they trust with their number compared with their email address.

The issue of trust is the great advantage that lies at the heart of SMS marketing. Because people are reluctant to give out their numbers, few businesses have those numbers, and so fewer marketing texts are sent compared with marketing emails. The result is that customers are unlikely to get bored with marketing texts the way they've become bored by marketing emails.

But trust is also the greatest obstacle that you, as a would-be SMS marketer, have to overcome. How do you persuade customers and potential customers to hand over their mobile numbers?

Obtaining those numbers comes down to your offering and your relationship with the customers you're targeting. SMS marketing isn't always great at converting absolutely new, cold customers who know nothing about your product or your brand (neither is email). But SMS is devastatingly effective when used on warm leads, or—in particular—when used to drive repeat business.

Let's imagine some scenarios:

• You run a restaurant. Some of your customers travel several miles to visit you, and you'd like them to come more often. You collect their mobile numbers and send them the occasional text message—not too many, maybe one every couple of weeks—telling them about a special offer or your Dish of the Day.
  
• You're an independent financial adviser. You use SMS to quickly notify customers when a great new product comes along.
  
• You run a bike shop, selling new bikes, accessories, and spares. You also offer servicing. You text your customers to tell them about new offers, or to tell them that their bike is ready to pick up, or to notify them when their order has come in.

Those scenarios are based on driving repeat business in situations where customers have a genuine, proven interest in your product or service. They are all, to use the technical term, examples of permission-based marketing.

Getting the Numbers

But how do you persuade your customers to hand over their mobile numbers, and let you use them on a continuing basis?

You'll first need to establish trust. Once you've done that, you'll have several options open to you. Broadly, methods of acquiring mobile numbers from your customers fall into two categories: indirect and direct.

1. Indirect acquisition means asking for your customers' numbers for purely practical reasons (e.g., letting them know their order has arrived, reminding them about service dates, confirming appointments). That tends to be very effective because customers generally find SMS notifications and reminders very useful. However, if you're planning to use the numbers for further marketing activity, you must get your customers' active permission. If you don't, you'll probably be breaking your country's data-protection regulations.
   
2. Direct acquisition means asking for your customers' numbers specifically for the purpose of telling them about products and offers. It's a more upfront approach that tends to have a slightly lower success rate than indirect acquisition, but it deals directly with the problem of permission.

Keeping the Numbers

Once you've gotten the mobile numbers, you need to make sure customers remain happy with your marketing. If a customer asks you to stop sending messages, in most countries the law requires that you do indeed stop.

So, to retain the right to use a customer's number, you have to keep that customer happy. Don't text too often (maybe one offer every two weeks, unless you're really sure of the customer's loyalty), and make sure you're sending genuinely good offers that are very likely to appeal to them.

Above all, make sure you're sticking to those data protection rules—both in your country and your recipient's country (if it's different from yours).

Different legal systems offer different levels of protection for consumers regarding data security and marketing, but it's best to do a bit of research before you start your campaign. If you understand the relevant laws, you shouldn't find them too much of a burden—and they'll help you deliver a legal, effective, customer-friendly campaign.

Using Technology

Another way to grab your customers' mobile numbers is a form on your site. That method is effective because it saves time: a number submitted online can be fed directly into your marketing database, ready for automated inclusion in the next round of marketing.

Of course, technology plays a role in how you'll actually deliver your messages. Obviously, you don't want to be manually sending each text from your own phone (your thumb would get pretty sore!). That's why software exists that allows "texting on the computer." You can send and receive bulk SMS from your computer; you can also manage and build SMS lists.