Since we started in 2005, Math-Drills.com has been an ad-supported website. What this means is that we can offer the end-user: parents, teachers, homeschoolers, etc. a product and still meet our financial needs by selling ad space on the website. Advertisers pay money to appear on our website usually because they think that you might be interested in the product they sell. We generally try to balance the intrusion of the ads with user experience. We realize that no-ads would be the best, but then we wouldn't exist without something to pay our bills.
We support student learning at no cost other than a little printer ink and paper. Every day, our worksheets are used in schools, homeschools, adult learning centers, special education classrooms, university and college courses, on kitchen tables, in cars on family trips, on interactive white boards, and in many other places.