We have 2 websites - let's call them website A and B.
Website A is about event management and website B is about sustainable events, so they are very similar, albeit with slightly different themes/goals.
In essence, website B is the child of website A.
How can I show on website B that it is powered by website A?
How can I promote website A through website B without having to put in obvious ads/banners/pop-ups?