There are a variety of ad servers out there, but large publishers have very specific needs. They could build their own ad servers, but the costs are prohibitive. Enter Kevel, an AdTech (advertising technology) company. Kevel gives publishers a set of APIs that allow them to build their own custom servers and then Kevel takes care of the complexity on the back end. This creates the best of both worlds: customization capabilities plus scalability at a great price.