In the common case, selling someone $50,000 of licenses is a $50,000 win for the company.
That actually sounds like a very uncommon case. Even fully client-side software has variable costs in the form of support costs.
Support costs aren't relevant to your parent's example, but they do imply another misalignment of incentives. If a salesperson's commission is based on revenue alone, she'll just as soon sell to a costly, high-maintenance customer as to a profitable, low-maintenance one.