To understand Cowboy Credits, I like to think of them as the fuel for a car: buying them once isn't enough to drive indefinitely.
You buy 12,345 sats of CC, and then each post, comment, or boost uses up some of them. When your balance reaches zero, you can no longer publish. Stacker News works this way to limit spam.
At first, I thought it was enough to top up each time: pay an invoice from Speed App, receive CC, publish until you run out, and then start again. But that's an endless loop.
The other option is to let Zaps contribute to replenishing your supply. If Speed App is linked as a Lightning address, the sats from Zaps can be sent there. Depending on the settings available in your account, you can also automatically convert some of these Zaps into CC. Go to Stacker News > Wallet > Settings and look for an option like “Autofill CC from zaps” or “Convert zaps to CC”. The wording may vary.
If this conversion is enabled, zaps can help maintain your CC balance—but it won't necessarily stay above zero if you don't receive enough.