While it's good to see WIS trying to advertise, I'm not sure a local radio spot is the best place to market a website to the global (or at the minimum, national) sports gaming community. Sure it can reach people but it's probably not the best bang for your buck (unless its free) and there are plenty of better avenues.
My personal suggestion would be a link and graphic with a short description on a website where you already know people interested in a particular sport will be visiting. Taylor the ad to that sport and show the game on WIS that aligns with what those people are already seeing on that site.
For example, if someone reads an article about major league baseball on a well-known sports website, have an ad on that pagbe for baseball simleagues or hardball dynasty. If someone is reading about NCAA basketball, put an ad on that page for HD. And so on.