For the Chicagoland area, premium us generally $1-1.20/gallon more. Sometimes GB or the station itself would run a deal of $.25/gal off using the app. When I fill my 19.5gal tank, it's easily saving $5 fill up, or about $20/mo or $280-300/yr.
At least it's somewhat benefiting me by selling my data where usually there's no perk at all. But when I learned just how bad, I'm definitely done. Basically you have no rights to your data, indefinitely, whether you're a customer or not. And the Allstate partnership is a big no from me.