Zalando's Biggest Challenge With Building an Ads Business

I wanted to ask you what's your maybe current or what's your biggest challenge with building the business the ads business basically at Zalando? So, you know, there were many, but let me pick one. How do we build a customer lifetime, say value prediction model that takes into account all the signals, factors in sales, returns, revenue from ads,. And is used as objective function to determine the kind of content to be shown on the platform. That's I would say was the is the one of the bigger challenges and we are working on it.