A promotional banner usually consists of an image, some text, a logo, and/or a link to the advertising company's website. But all promotional banners have the same function: To entice a visitor to click on an image they see on a web page.
TWIG : Betclic/_common/_twig/_components/_banners.twig
CSS : Betclic/_tactics/_common/_css/_components/_banner/_banner.scss
Betclic/_tactics/_common/_css/_components/_banner/_referral.scss
JS : Betclic/_common/_js/_banners.js
Referral banners can be present in all universes from the moment the user is logged in.