It is a marketing strategy that focuses on creating and distributing valuable, attractive, and ongoing content to attract a target audience and build a long-term relationship with them. It aims to provide content that meets the needs of the audience or solves a problem they have, rather than focusing only on directly promoting the product or service.

Characteristics of content marketing
1. Content value: The content must be of actual value to the target audience.
2. Attraction and interest: Content marketing is characterized by its ability to attract attention and interest over time.
3. Continuity: Content marketing needs to provide ongoing content over time to build a strong relationship with the audience.
4. Interaction: Content marketing encourages interaction and participation with the audience.
5. Shareability: Good content can be easily shared across social media and other digital platforms.

Benefits of content marketing
1. Building trust and credibility: It helps build a relationship of trust between the brand and the audience.
2. Search engine optimization : It leads to an increase in the site's ranking in search engine results.
3. Increase conversions: It can increase conversion rates by providing useful information that encourages decision-making.
4. Achieve engagement: Increases audience engagement with the brand.
5. Support other marketing strategies: It can complement and support other marketing efforts such as email marketing.

Advantages of content marketing
1. Lower cost compared to traditional advertising: It is usually more cost-effective in the long run.
2. Access to a wider audience: A diverse audience can be reached through the Internet.
3. Flexibility in using different media: Content can be delivered via video, blogs, images, and articles.

Cons of content marketing
1. It requires time and effort: It requires a lot of time and effort to create high-quality content regularly.
2. It may not give immediate results: It takes time to build an audience and increase engagement.
3. High competition: Due to the widespread use of this strategy, competition can be fierce. 

Modern examples of content marketing
1. HubSpot blog: It is one of the most famous examples of content marketing as it provides useful articles and guides in the field of digital marketing.
2. Coca-Cola campaigns via video: It provides visual content that tells stories and inspires the audience.
3. Google Tutorials: Google offers free educational content that helps audiences use its products effectively.

Content marketing is a powerful tool for building long-term relationships with your target audience by providing useful and engaging content. It can lead to increased trust, improved search rankings, and conversions, but it takes a lot of time and effort and may not give immediate results. With high competition, businesses must focus on providing high-quality, valuable content to stay ahead.