We calculate the amount of karma credits that you pay for a shoutout based on how many people saw and clicked on your ad. It works the same way when you earn karma credits for shouting out one of your community of brands.
We use karma credits as our internal currency. You might pay hundreds of credits or just a few for any shout out depending on the audience of the brand shouting you out. Don't worry we work it all out for you and you can keep an eye on your karma credit balance here.