As multiple commenters note, UK and EU interchange is significantly lower than that in the US. So the rewards market tends to be different as a result.
That said, launching this in the UK would still be attractive to us. We don't think rewards are the primary thing businesses are looking for.
As we talked to founders, it seems like they all want a corporate card early on for their business spending (to get it off personal cards). As the business adds employees, they need a sensible way to keep tabs on spending without the expensing process being really painful. I think that's just as relevant in the UK, with the added detail of multi-currency spending being more relevant.