It is a marketing strategy that relies on sending short messages (SMS) to customers' phones to promote goods or services, or to send important notifications and updates. These messages are often short and direct, and are used to reach customers quickly and personally.

Characteristics of text message marketing:
1. Fast delivery: Messages reach customers' phones directly in a very short time.
2. Personalization: Messages can be personalized based on customer data, such as name or customized offers.
3. High read rate: A large percentage of text messages are opened and read within minutes.
4. Low cost: Compared to some other forms of marketing, the cost of sending text messages is relatively low.

Benefits of text message marketing:
1. Precise targeting: You can send messages to specific categories of customers based on their preferences and behaviors.
2. Increase engagement: Text messages can encourage customers to interact faster, such as visiting a website or participating in a specific campaign.
3. Enhance loyalty: Reminding customers of special offers and discounts can enhance their loyalty to the brand.
4. Improved communication: Text messages can be used to communicate with customers immediately, such as confirming appointments or providing customer service.

Disadvantages of text message marketing:
1. Annoyance: If messages are too many or irrelevant, customers may become annoyed and choose to unsubscribe.
2. Length restrictions: Text messages are short, which limits the amount of information that can be communicated.
3. Compliance with laws: Data protection and privacy laws must be complied with, such as obtaining customer consent before sending messages.
4. Technical challenges: Messages may be affected by connection quality or be lost due to technical issues.

Examples of text message marketing:
- Restaurant company: Send promotional text messages to customers about lunch or dinner specials.
- Bank: Notify customers of loan due dates or updates to their accounts.
- E-commerce company: Send discount codes to customers to encourage them to complete purchases through the site.

Text message marketing is an effective and fast way to reach customers and provide important offers or notifications. It has the advantage of rapid access and a high read rate, but it can be annoying if not used carefully. It is a powerful tool to enhance customer engagement and increase customer loyalty if implemented correctly.