Bs
B6 should add a "BS" fare like the WN one that would be:
Refundable
Always have a seat avaible in first 10 rows
Free movie
Free alcoholic drink
More TB points
Priority boarding
B6 could charge $25-50 more depending on route for the BS type airfare. This would kill two birds with one stone 1. increasing revenue 2. adding refundable fares