I worked at both around 94-95. IIRC, RS's commission started paying if you could sell more than an avg $75/hr for a pay period and a bonus rate if you hit $115/hr.
BB made you hit a minimum of like $2000/day if you were in the computer dept.
Edit: the RS I worked at was across the street from a mall that had an RS in it. I very rarely made commission.
Edit: the RS I worked at was across the street from a mall that had an RS in it. I very rarely made commission.