Using a specific keyword multiple times in a piece of content was a popular SEO technique in the past. However, this practice, also known as keyword stuffing, is now considered a black hat SEO technique and can harm a website's ranking. The current best practice is to use a keyword naturally and judiciously, ensuring it fits within the context of the content. It is recommended to use the target keyword, such as 50 cent leather jacket only once in the content to avoid over-optimization and maintain a natural flow of the text. Additionally, using synonyms, related terms, and variations of the target keyword can help enhance the content's relevance and improve its ranking without risking any penalty. By following this approach, a website can create high-quality content that serves both the audience and search engines' needs.