Are you sure, because if you do you could make millions
The description text Google uses is based on their algorithm which they're very secretive about. Sometimes it's the meta description, sometimes it's the first paragraph. It's all guesswork. It can also take months toupdate, depending on the amount of traffic to your site and how often Google spiders you.
All you can really do is to write good descriptive copy on each page, relevant to what the url and keywords are, and then pray to every God that google uses a description for your listing that you're happy with.