CodeIgniter had several characteristics that made it appealing in the market:

1. Lightweight and Fast: CodeIgniter is known for its lightweight footprint and high performance. It doesn’t require extensive server resources, making it suitable for a wide range of hosting environments.
2. Simplicity and Ease of Learning: CodeIgniter’s simple and straightforward documentation, along with its small learning curve, attracts developers. It’s accessible for both beginners and experienced developers.
3. MVC Architecture: CodeIgniter follows the MVC pattern, which promotes code organization, separation of concerns, and maintainability.
4. Active Community: Despite not being as large as some other frameworks, CodeIgniter has an active community that regularly contributes to its development, provides support, and creates extensions.
5. Security Features: It offers built-in security features, such as input data filtering and XSS (Cross-Site Scripting) prevention, which are crucial for web application security.
6. Flexibility: CodeIgniter doesn’t impose strict coding rules, offering developers the flexibility to choose their preferred coding practices and libraries.
7. Extensive Library: It includes a rich set of libraries and helpers that simplify common tasks like database interaction, form handling, and session management.

However, it’s essential to note that the web development landscape is constantly evolving, and the “best” framework can change over time. The popularity and suitability of frameworks can vary depending on project requirements, industry trends, and developer preferences.

Regarding CodeIgniter certification, it can improve your career in several ways:

1. Validation of Expertise: A CodeIgniter certification demonstrates your proficiency and in-depth knowledge of the framework. It serves as tangible proof of your skills to potential employers.
2. Competitive Advantage: In a competitive job market, having a certification sets you apart from other candidates, increasing your chances of landing a job or promotion.
3. Wider Job Opportunities: Many companies specifically seek developers with CodeIgniter expertise. Certification broadens your job opportunities, as businesses look for qualified individuals to work on their web projects.
4. Career Advancement: Certified professionals often receive higher compensation and are considered for more senior roles and responsibilities within organizations.
5. Client Trust: Freelancers and consultants can use certification to build trust with clients, showcasing their specialized skills and commitment to quality.
6. Continuous Learning: Preparing for certification encourages ongoing learning and staying updated with the latest developments in the framework.