In what is internally referred to as "The Business" (ie. any of the multitude of direct sales offices that sprung out of DS-Max, Cydcor, Granton, Smartcircle, Credico etc.), this is a term referring to hitting ones sales goal of selling enough to earn $100 personal profit for the day. This can equate to a certain number of sales dependent upon the campaign. For example, if one earns $50 commission per sale and then "ringing the bell" entails closing two sales.
This is not only an idiomatic expression as it refers to the literal ringing of a bell after returning to the office from a day in the field. All reps who earned the minimum $100 profit ring a large bell signifying their results and are congratulated by their fellow sales reps in a raucous, high-energy ceremony.