Best search engines

The best search engines I have come across are BING and Swag Bucks. They are search engines that both reward you with many different prizes for doing what you normally do. Bing rewards you points every other search up to 20 points a day. While swagbucks rewards you points randomly when you search for all different amounts of points. When you earn enough points on each site you can redeem them in their rewards stores for prizes such as gift cards, cash and so much more. Why do searches for free when you can get free stuff for doing it.