With a 98% open rate (90% within the first three minutes), SMS is the most effective marketing channel when you need to get a message out to your customers. But for all its effectiveness, it can be hard to get SMS subscribers and even harder to retain them. The Federal Communications Commission’s (FCC) regulations on text message marketing set forth in the Telephone Consumer Protection Act (TCPA) require businesses to obtain consumers’ express permission before sending a single text and they require that consumers be allowed to opt out at any point. Most bulk SMS services include instructions for cancelling in every text message and are programmed to recognize words like “STOP”, “UNSUBSCRIBE”, “CANCEL,” and others and automatically unsubscribe recipients who reply with any of these words.

Because it’s so easy to unsubscribe, and because SMS is a rather intimate channel where consumers are more aware of unwanted communications, the unsubscribe rate for SMS is approximately seven times higher than email’s (3.7% compared to email’s .5%). Limiting opt-outs and retaining SMS subscribers should be a primary objective for mobile marketers. The following six tips can help.

Don’t make the introductory too good

Making an introductory offer for first-time SMS subscribers is a standard and commonly used practice. But if the introductory is too good, it sets an expectation for future offs that businesses simply can’t afford to live up to and people opt out when future offers don’t measure up. Promising a coupon or deal to subscribers is a fine tactic, but make sure that the introductory offer is in line with offers you will be texting out to your subscriber list in the future.

Let subscribers know who’s texting them

The average consumer who subscribes to your SMS list will probably subscribe to at least several others. Since many won’t bother to save your short code into their phone as a contact, their inbox will just have a number of text conversations from random strings of numbers and you run the risk of being deleted along with all the rest when the person cleans out their inbox. You can encourage them to save the number as a contact under your name but you shouldn’t assume they will. Include your name towards the beginning of each text so that at the very least, they can see from the message preview who is texting.

Send relevant offers

Customers need to perceive value in being an SMS subscriber of your business. If they find that they’re ignoring 90% of your texts or more because they aren’t relevant, it’s just a matter of time before they unsubscribe. You can avoid this by segmenting your SMS audience according to their preferences and interests so that the messages you’re sending is more likely to be relevant to each recipient.

Be mindful of timing and frequency

People unsubscribe when they feel the intrusion isn’t worth the occasional offer. The major disadvantage of text messaging is also its primary advantage: it’s intrusive. Open rates are high because most phones are set to give an auditory or tactile notification to their users when a message is received but opt ou rates are high for the same reason. To limit opt outs for this reason, make sure you’re not texting too often or at inconvenient times. It may be wise to segment your audience according to their preferred contact time as well.

Give them the option to resubscribe

Include in the automated response to opt-outs instructions for opting back in. Some customers may make a spur-of-the-moment decision to opt out during a particularly stressful time or when they’re trying to cut down on digital interference but may reconsider later. They may unsubscribe but not delete the text conversation and decide to come back to it later and resubscribe.

Don’t lose sleep over opt-outs

Just come to terms with the fact that you won’t retain every SMS subscriber. Some will opt out and never come back. Try not to lose any sleep over it; they’re not your ideal customers anyways. Instead think of the money you save when the unreceptive subscribers remove themselves from your list and focus on providing value for the subscribers who remain.