I normally avoid it as I find it too noisy -- filled with repeat emails from brands that I don't care about. It feels like too much work personally to unsubscribe from all irrelevant senders. And yet, while browsing it, I did notice a lot of latent value in relevant deals and discounts.
Would any UX changes unlock value from this tab? Some that come to mind include:
1) Better UI to declare which brands I care about.
2) Order messages based on promotional value rather than date received (admittedly weird for the email context)
3) User controls for how many messages received per brand per time interval.
4) Option to automatically unsubscribe if user does not respond to N messages from a given brand.
5) Rules to filter out deals / discounts that do not clear a specified threshold (i.e. save at least $20).