There are several reasons to use an SSL certificate, including:

1. Security: The main purpose of an SSL certificate is to ensure the security of data exchange between a web server and a browser. By using SSL, all information exchanged between the browser and server is encrypted, making it more difficult for hackers and other malicious parties to gain access to this information.

2. Trust: When a website has an SSL certificate, it is displayed in the browser's address bar, letting users know that the website is secure and their data is protected. This can lead to increased trust from the user in the website and the company that manages the website.

3. SEO: Search engines like Google have indicated that SSL certificates can be a factor in determining the ranking of a website in search results. Websites that use SSL can therefore be ranked higher in search results than those that do not.

Overall, using an SSL certificate provides benefits in terms of security, trust, and search engine optimization, making it an important consideration for any business that manages a website.