Generators that import ai-text-plugin or text-to-image-plugin have an ad displayed at the bottom of the page which funds the GPUs required to support those plugins. If you don't import either of those plugins on your generator, then no ads are ever shown.

Note that if you're logged in, then no ads are ever shown, even on pages that import ai-text-plugin or text-to-image-plugin. The idea is that you're contributing to the perchance ecosystem/community via creating stuff (that's the whole point of having an account on perchance), instead of via seeing ads.