Very similar question was asked 5 years ago. It got a good answer, I will paste it here for you.
Points have no monetary value and there are no prizes, no cigars no nada, it's really just the satisfaction of helping others, no strings attached, or possibly bragging rights (big deal).There are seven levels, more points give you more participation rights so it can also be an ego thing and keep us interested. This will help you get started. To move up answer lots of questions, the maximum you can do every day trying for best answer which gives you ten points, and avoid asking questions that costs you five points. When you ask a question be sure to return and pick a best answer to get 3 points back.Click the link below to see the complete points setup.
Keep this in mind. When you post on YA be mindful of what you post, your posts become the property of Yahoo and in most cases cannot be deleted.