OpenDNS is a service that many people swear by, and it’s become an integral part of the Internet for hundreds of thousands of users. With it you can filter content, protect against phishing, block adult sites, and even have it correct common typos in URL’s. For that reason we’ve seen businesses and schools alike flocking to OpenDNS as a central way to control the content accessible by its users.

According to TechCrunch they currently have over 500,000 registered accounts, but you don’t have to register to take advantage of their services. There are likely a lot more users than that since everyone doesn’t need an account, and OpenDNS has said that one particular school with a single account has over 36,000 different users.

OpenDNS serves up over 7 billion DNS queries each day, and they have to earn money one way or another. What they are doing is capitalizing on unrecognizable URL’s that are entered into the address bar by users. When that happens they show search results that are supposed to help users find what they are looking for, and along side the results are ads (highlighted in the screenshot above). OpenDNS gets requests for over 2 million searches a day, and for them that translates into $20,000 per day in revenue. That’s about $7.3 million per year. Not too shabby.

From what I’ve read most people don’t mind the ads intermingled in the search results, but what they would like to see is Google powering the searches. Currently Yahoo! is the provider they’ve chosen, and that’s likely because they offered more money than Google.