You can take advantage of SHOUTcast's new partnership with TargetSpot and allow them to play ads on your stream. Payments are through Paypal and sent when you reach $100 in ad revenue.
First ensure you have set up your station with the new SHOUTcast interface as indicated on this page https://account.hiredhosting.com/index.php?rp=/knowledgebase/1041/How-to-set-up-your-SHOUTcast-directory-listing.html
Login to the SHOUTcast Website and station interface https://radiomanager.shoutcast.com/
Choose the stream you want to monetize, then click on the Monetize link on the left
You'll need to set up your payment method and agree to the terms.
Choose the amount of time you want the ads to play (duration), and activate ads.
To trigger the ads, you'll need to create a song or ad of your own the same amount of time you picked for your ad duration. The file must have the mp3 tag set to "Advert:"
Both the artist and song tag must be Advert:
Schedule your special track to play whenever you like using the Centova playlist system.