The article makes it pretty clear.

Third paragraph:

"...communications systems for real-time reporting on a bin’s capacity. By allowing municipalities to service the BigBellys only when they are full, they are saving hundreds of thousands of gallons of fuel annually across all BigBelly units."

Fourth paragraph:

"...information gained from each compactor allows waste managers to optimize collection schedules and routes. Before BigBelly, trash collectors had to clear out each can three times a day. Now they do so three times a week."