Tracking pixels and unsubscribe links hosted on a shared domain are a shared liability. If another sender burns that domain's reputation, your links carry the damage into your recipients' spam filters — and you did nothing wrong.
Campaigns sending from a domain you manage in Sellvance now serve their unsubscribe links and tracking pixels from that same domain. The links match the sender, which is both better for deliverability and less alarming to a recipient who hovers over them.
It also removes a mismatch that filters actively score against: a message from one domain whose links all point at another.